Merge pull request #8718 from readthedocs/humitos/test-py38

Tests: run tests with Python3.8 in CircleCI

Author: humitos

.circleci/config.yml

@@ -15,7 +15,7 @@ jobs:
       - run: git submodule sync
       - run: git submodule update --init
       - run: pip install --user tox
-      - run: tox -e py36,codecov
+      - run: tox -e py38,codecov
 
   tests-embedapi:
     docker: