Merge branch 'master' into update_requirements

Author: altendky

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ on:
 jobs:
   ci:
     runs-on: ${{ matrix.os }}
-    container: docker://altendky/hydra:ubuntu-3-minors
+    container: docker://altendky/hydra:ubuntu-20.04-3-minors
     strategy:
       fail-fast: false
       matrix:
@@ -21,6 +21,7 @@ jobs:
           - py36,report,codecov
           - py37,report,codecov
           - py38,report,codecov
+          - py39,report,codecov
           - pypy3,report,codecov
           - doc
           - check

tox.ini

@@ -5,7 +5,7 @@ envlist =
     clean,
     check,
     doc,
-    {py36,py37,py38,pypy3},
+    {py36,py37,py38,py39,pypy3},
     report
 
 [testenv]
@@ -14,6 +14,7 @@ basepython =
     py36: {env:TOXPYTHON:python3.6}
     py37: {env:TOXPYTHON:python3.7}
     py38: {env:TOXPYTHON:python3.8}
+    py39: {env:TOXPYTHON:python3.9}
     {doc,spell,bootstrap,clean,check,report,codecov}: {env:TOXTOOLPYTHON:python3.8}
 setenv =
     PYTHONPATH={toxinidir}/tests