Travis don't support Python 3.9.0 yet.

.github/workflows/python_ci.yml

@@ -12,12 +12,12 @@ jobs:
     name: "Python ${{ matrix.python-version }}"
     runs-on: "windows-2019"
     env:
-      USING_COVERAGE: '3.6,3.7,3.8,3.9'
+      USING_COVERAGE: '3.6,3.7,3.8'
 
     strategy:
       fail-fast: False
       matrix:
-        python-version: ["3.6","3.7","3.8","3.9"]
+        python-version: ["3.6","3.7","3.8"]
 
 
     steps:

.github/workflows/python_ci_macos.yml

@@ -12,12 +12,12 @@ jobs:
     name: "Python ${{ matrix.python-version }}"
     runs-on: "macos-latest"
     env:
-      USING_COVERAGE: '3.6,3.7,3.8,3.9'
+      USING_COVERAGE: '3.6,3.7,3.8'
 
     strategy:
       fail-fast: False
       matrix:
-        python-version: ["3.6","3.7","3.8","3.9"]
+        python-version: ["3.6","3.7","3.8"]
 
 
     steps:

.travis.yml

@@ -8,7 +8,7 @@ python:
   - '3.6'
   - '3.7'
   - '3.8'
-  - '3.9'
+  - '3.9-dev'
 
 arch:
   - amd64
@@ -40,7 +40,7 @@ jobs:
       arch: arm64
     - python: '3.8'
       arch: arm64
-    - python: '3.9'
+    - python: '3.9-dev'
       arch: arm64
 
   include:

repo_helper.yml

@@ -19,7 +19,7 @@ python_versions:
   - 3.6
   - 3.7
   - 3.8
-  - 3.9
+  - 3.9-dev
 
 additional_ignore:
   - wip-shields-block.py

tox.ini

@@ -19,13 +19,13 @@
 #     * pytest
 
 [tox]
-envlist = py36, py37, py38, py39, mypy, build
+envlist = py36, py37, py38, py39-dev, mypy, build
 skip_missing_interpreters = True
 requires = pip>=20.2.1
 isolated_build = True
 
 [envlists]
-test = py36, py37, py38, py39
+test = py36, py37, py38, py39-dev
 qa = mypy, lint
 cov = py36, coverage
 
@@ -34,14 +34,14 @@ python =
     3.6: py36, build, mypy
     3.7: py37, build
     3.8: py38, build
-    3.9: py39, build
+    3.9-dev: py39-dev, build
 
 [gh-actions]
 python =
     3.6: py36, build
     3.7: py37, build
     3.8: py38, build
-    3.9: py39, build
+    3.9-dev: py39-dev, build
 
 [testenv]
 setenv =