diff --git a/.circleci/config.yml b/.circleci/config.yml
new file mode 100644
index 0000000..625c819
--- /dev/null
+++ b/.circleci/config.yml
@@ -0,0 +1,31 @@
+version: 2
+
+jobs:
+  tests:
+    docker:
+      - image: circleci/python:3.6
+        environment:
+          PIPENV_VENV_IN_PROJECT=1
+          PIPENV_IGNORE_VIRTUALENVS=1
+    steps:
+      - checkout
+      - setup_remote_docker:
+          version: 20.10.6
+          docker_layer_caching: true
+      - run:
+          name: Setup
+          command: |
+            pip install pipenv
+            pipenv install
+      - run:
+          name: Build Docker image
+          command: docker build -t readthedocs/build:7.0 .
+      - run:
+          name: Run tests
+          command: pipenv run pytest -m image_70
+
+workflows:
+  version: 2
+  tests:
+    jobs:
+      - tests
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 1deca5b..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,23 +0,0 @@
-language: python
-python:
-  - "3.6"
-env:
-  global:
-    - PIPENV_VENV_IN_PROJECT=1
-    - PIPENV_IGNORE_VIRTUALENVS=1
-before_install:
-  - pip install pipenv
-install:
-  - pipenv install
-script:
-  - docker build -t readthedocs/build:7.0 .
-  - pipenv run pytest -m image_70
-
-
-branches:
-  only:
-    - master
-    - releases/5.x
-    - releases/6.x
-    - releases/7.x
-    - releases/8.x
diff --git a/Dockerfile b/Dockerfile
index ad7d27f..4a6509c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -14,17 +14,21 @@ ENV PYTHON_VERSION_36 3.6.12
 ENV PYTHON_VERSION_37 3.7.9
 ENV PYTHON_VERSION_38 3.8.6
 ENV PYTHON_VERSION_39 3.9.1
+ENV PYTHON_VERSION_310 3.10.0b4
 ENV PYPY_VERSION_35 pypy3.5-7.0.0
-# Note: 4.7.12.1 drastically increases memory usage
-ENV CONDA_VERSION 4.6.14
+# Latest miniconda version is Miniconda3-py39_4.10.1, but it's not available for x86_64
+ENV CONDA_PYTHON_VERSION py39
+ENV CONDA_VERSION 4.9.2
 LABEL python.version_27=$PYTHON_VERSION_27
 LABEL python.version_35=$PYTHON_VERSION_35
 LABEL python.version_36=$PYTHON_VERSION_36
 LABEL python.version_37=$PYTHON_VERSION_37
 LABEL python.version_38=$PYTHON_VERSION_38
 LABEL python.version_39=$PYTHON_VERSION_39
+LABEL python.version_310=$PYTHON_VERSION_310
 LABEL pypy.version_35=$PYPY_VERSION_35
 LABEL conda.version=$CONDA_VERSION
+LABEL conda.python_version=$CONDA_PYTHON_VERSION
 
 # System dependencies
 RUN apt-get -y update
@@ -75,6 +79,7 @@ RUN apt-get install -y \
       libncurses5-dev \
       libncursesw5-dev \
       libssl-dev \
+      libxmlsec1-dev \
       llvm \
       make \
       python-openssl \
@@ -141,14 +146,6 @@ RUN apt-get -y install \
       auxlib \
       virtualenv==$RTD_VIRTUALENV_VERSION
 
-# sphinx-js dependencies: jsdoc and typedoc (TypeScript support)
-RUN apt-get -y install \
-      nodejs \
-      npm \
- && npm install --global \
-      jsdoc \
-      typedoc
-
 # UID and GID from readthedocs/user
 RUN groupadd --gid 205 docs
 RUN useradd -m --uid 1005 --gid 205 docs
@@ -157,10 +154,10 @@ USER docs
 WORKDIR /home/docs
 
 # Install Conda
-RUN curl -L -O https://repo.continuum.io/miniconda/Miniconda2-${CONDA_VERSION}-Linux-x86_64.sh
-RUN bash Miniconda2-${CONDA_VERSION}-Linux-x86_64.sh -b -p /home/docs/.conda/
+RUN curl -L -O https://repo.continuum.io/miniconda/Miniconda3-${CONDA_PYTHON_VERSION}_${CONDA_VERSION}-Linux-x86_64.sh && \
+    bash Miniconda3-${CONDA_PYTHON_VERSION}_${CONDA_VERSION}-Linux-x86_64.sh -b -p /home/docs/.conda/ && \
+    rm -f Miniconda3-${CONDA_PYTHON_VERSION}_${CONDA_VERSION}-Linux-x86_64.sh
 ENV PATH $PATH:/home/docs/.conda/bin
-RUN rm -f Miniconda2-${CONDA_VERSION}-Linux-x86_64.sh
 
 # Install Rust
 ENV RTD_RUST_VERSION 1.46.0
@@ -177,6 +174,7 @@ ENV PATH /home/docs/.pyenv/shims:$PATH:/home/docs/.pyenv/bin
 
 # Install supported Python versions
 RUN pyenv install $PYTHON_VERSION_27 && \
+    pyenv install $PYTHON_VERSION_310 && \
     pyenv install $PYTHON_VERSION_39 && \
     pyenv install $PYTHON_VERSION_38 && \
     pyenv install $PYTHON_VERSION_37 && \
@@ -185,6 +183,7 @@ RUN pyenv install $PYTHON_VERSION_27 && \
     pyenv install $PYPY_VERSION_35 && \
     pyenv global \
         $PYTHON_VERSION_27 \
+        $PYTHON_VERSION_310 \
         $PYTHON_VERSION_39 \
         $PYTHON_VERSION_38 \
         $PYTHON_VERSION_37 \
@@ -202,6 +201,13 @@ RUN pyenv local $PYTHON_VERSION_27 && \
 
 ENV RTD_PIP_VERSION 20.0.2
 ENV RTD_SETUPTOOLS_VERSION 45.2.0
+
+# NOTE: numpy is not installed by default because it's not built for Python 3.10 yet
+RUN pyenv local $PYTHON_VERSION_310 && \
+    pyenv exec pip install --no-cache-dir -U pip==$RTD_PIP_VERSION && \
+    pyenv exec pip install --no-cache-dir -U setuptools==$RTD_SETUPTOOLS_VERSION && \
+    pyenv exec pip install --no-cache-dir virtualenv==$RTD_VIRTUALENV_VERSION
+
 RUN pyenv local $PYTHON_VERSION_39 && \
   pyenv exec pip install --no-cache-dir -U pip==$RTD_PIP_VERSION && \
   pyenv exec pip install --no-cache-dir -U setuptools==$RTD_SETUPTOOLS_VERSION && \
@@ -238,6 +244,22 @@ RUN pyenv local $PYPY_VERSION_35 && \
     pyenv exec pip install --no-cache-dir -U setuptools==$RTD_SETUPTOOLS_VERSION && \
     pyenv exec pip install --no-cache-dir virtualenv==$RTD_VIRTUALENV_VERSION
 
+# NOTE: this is moved to the bottom because apt-get finds some incompatibilities
+# between packages and uninstall them:
+# The following packages will be REMOVED:
+#  libmysqlclient-dev libssl-dev libxmlsec1-dev
+# As libssl-dev and libxmlsec1-dev are required to build Python with pyenv,
+# we first build Python versions and then install these packages
+# sphinx-js dependencies: jsdoc and typedoc (TypeScript support)
+USER root
+RUN apt-get -y install \
+    nodejs \
+    npm \
+    && npm install --global \
+    jsdoc@3.6.6 \
+    typedoc@0.20.20
+
+USER docs
 WORKDIR /
 
 CMD ["/bin/bash"]
diff --git a/tests/test_dependencies.py b/tests/test_dependencies.py
index ee5f5c2..10b1486 100644
--- a/tests/test_dependencies.py
+++ b/tests/test_dependencies.py
@@ -14,15 +14,17 @@ def test_miniconda():
     base_url = 'https://repo.continuum.io/miniconda'
     dockerfile = get_dockerfile()
     conda_version = dockerfile.envs.get('CONDA_VERSION')
+    conda_python_version = dockerfile.envs.get('CONDA_PYTHON_VERSION')
     latest = requests.head(
-        '{base}/Miniconda2-latest-Linux-x86_64.sh'.format(
+        '{base}/Miniconda3-latest-Linux-x86_64.sh'.format(
             base=base_url
         )
     )
     current = requests.head(
-        '{base}/Miniconda2-{version}-Linux-x86_64.sh'.format(
+        '{base}/Miniconda3-{conda_python_version}_{conda_version}-Linux-x86_64.sh'.format(
             base=base_url,
-            version=conda_version,
+            conda_python_version=conda_python_version,
+            conda_version=conda_version,
         )
     )
     assert current.headers['etag'] == latest.headers['etag']
diff --git a/tests/test_versions.py b/tests/test_versions.py
index 773971e..7e6aa3e 100644
--- a/tests/test_versions.py
+++ b/tests/test_versions.py
@@ -1,5 +1,4 @@
 import pytest
-from docker import APIClient
 
 from .utils import run_command_in_container
 
@@ -57,6 +56,7 @@ def test_command_versions_image_master(command, expected_output):
         ('python3.7 --version', 'Python 3.7.9'),
         ('python3.8 --version', 'Python 3.8.6'),
         ('python3.9 --version', 'Python 3.9.1'),
+        ('python3.10 --version', 'Python 3.10.0b4'),
         ('pypy3.5 --version', 'Python 3.5.3 (928a4f70d3de7d17449456946154c5da6e600162, Feb 09 2019, 11:50:43)\n[PyPy 7.0.0 with GCC 8.2.0]'),
         # pip
         ('python2 -m pip --version', "pip 20.0.2 from /home/docs/.pyenv/versions/2.7.18/lib/python2.7/site-packages/pip (python 2.7)"),
@@ -65,6 +65,7 @@ def test_command_versions_image_master(command, expected_output):
         ('python3.7 -m pip --version', "pip 20.0.2 from /home/docs/.pyenv/versions/3.7.9/lib/python3.7/site-packages/pip (python 3.7)"),
         ('python3.8 -m pip --version', "pip 20.0.2 from /home/docs/.pyenv/versions/3.8.6/lib/python3.8/site-packages/pip (python 3.8)"),
         ('python3.9 -m pip --version', "pip 20.0.2 from /home/docs/.pyenv/versions/3.9.1/lib/python3.9/site-packages/pip (python 3.9)"),
+        ('python3.10 -m pip --version', "pip 20.0.2 from /home/docs/.pyenv/versions/3.10.0b4/lib/python3.10/site-packages/pip (python 3.10)"),
         # setuptools
         ('python2 -c "import setuptools; print(setuptools.__version__)"', "44.0.0"),
         ('python3.5 -c "import setuptools; print(setuptools.__version__)"', "45.2.0"),
@@ -72,6 +73,7 @@ def test_command_versions_image_master(command, expected_output):
         ('python3.7 -c "import setuptools; print(setuptools.__version__)"', "45.2.0"),
         ('python3.8 -c "import setuptools; print(setuptools.__version__)"', "45.2.0"),
         ('python3.9 -c "import setuptools; print(setuptools.__version__)"', "45.2.0"),
+        ('python3.10 -c "import setuptools; print(setuptools.__version__)"', "45.2.0"),
         # virtualenv
         ('python2 -m virtualenv --version', 'virtualenv 20.0.7 from /home/docs/.pyenv/versions/2.7.18/lib/python2.7/site-packages/virtualenv/__init__.pyc'),
         ('python3.5 -m virtualenv --version', 'virtualenv 20.0.7 from /home/docs/.pyenv/versions/3.5.10/lib/python3.5/site-packages/virtualenv/__init__.py'),
@@ -79,12 +81,15 @@ def test_command_versions_image_master(command, expected_output):
         ('python3.7 -m virtualenv --version', 'virtualenv 20.0.7 from /home/docs/.pyenv/versions/3.7.9/lib/python3.7/site-packages/virtualenv/__init__.py'),
         ('python3.8 -m virtualenv --version', 'virtualenv 20.0.7 from /home/docs/.pyenv/versions/3.8.6/lib/python3.8/site-packages/virtualenv/__init__.py'),
         ('python3.9 -m virtualenv --version', 'virtualenv 20.0.7 from /home/docs/.pyenv/versions/3.9.1/lib/python3.9/site-packages/virtualenv/__init__.py'),
+        ('python3.10 -m virtualenv --version', 'virtualenv 20.0.7 from /home/docs/.pyenv/versions/3.10.0b4/lib/python3.10/site-packages/virtualenv/__init__.py'),
         # others
         ('node --version', 'v8.10.0'),
         ('npm --version', '3.5.2'),
-        ('conda --version', 'conda 4.6.14'),
+        ('conda --version', 'conda 4.9.2'),
         ('cargo --version', 'cargo 1.46.0 (149022b1d 2020-07-17)'),
         ('git --version', 'git version 2.17.1'),
+        ('jsdoc --version', 'JSDoc 3.6.6 (Sun, 20 Sep 2020 02:25:14 GMT)'),
+        ('cat /usr/local/lib/node_modules/typedoc/package.json | grep -E "version.:"', '"version": "0.20.20"'),
     ]
 )
 def test_command_versions_image_70(command, expected_output):
diff --git a/tests/utils.py b/tests/utils.py
index f403851..516e7ef 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -1,8 +1,9 @@
-from docker import APIClient
+import docker
 
 
 def run_command_in_container(container_image, command):
-    client = APIClient()
+    # CircleCI exports environment variables that ``.from_env()`` uses
+    client = docker.from_env().api
 
     # Create the container
     container = client.create_container(