Add python 3.9 support

Author: mcproger

.travis.yml

@@ -3,7 +3,9 @@ python:
   - "3.6"
   - "3.7"
   - "3.8"
+  - "3.9"
 install:
+  - gem install chef-utils -v 16.6.14
   - pip install -r requirements_dev.txt
   - pip install -e .
   - gem install mdl

requirements_dev.txt

@@ -13,8 +13,8 @@ flake8-print==3.1.4
 flake8-quotes==3.0.0
 flake8-string-format==0.3.0
 flake8-todo==0.7
-mypy==0.740
-flake8-annotations-complexity==0.0.4
+mypy==0.790
+flake8-annotations-complexity==0.0.6
 flake8-annotations-coverage==0.0.4
 flake8-cognitive-complexity==0.0.2
 safety==1.9.0

setup.py

@@ -34,6 +34,7 @@ def get_long_description() -> str:
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
     ],
     packages=find_packages(),
     include_package_data=True,