Move CI to GitHub Actions (#7903)

* Recreate all the jobs on GitHub Actions
* Upgrade to Ubuntu 20.04
* Upgrade base/docs/dist to Python 3.9

Author: adamchainz

.github/workflows/main.yml

@@ -0,0 +1,57 @@
+name: CI
+
+on:
+  push:
+    branches:
+    - main
+  pull_request:
+
+jobs:
+  tests:
+    name: Python ${{ matrix.python-version }}
+    runs-on: ubuntu-20.04
+
+    strategy:
+      matrix:
+        python-version:
+        - '3.6'
+        - '3.7'
+        - '3.8'
+        - '3.9'
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - uses: actions/cache@v2
+      with:
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-pip-${{ hashFiles('requirements/*.txt') }}
+        restore-keys: |
+          ${{ runner.os }}-pip-
+
+    - name: Upgrade packaging tools
+      run: python -m pip install --upgrade pip setuptools virtualenv wheel
+
+    - name: Install dependencies
+      run: python -m pip install --upgrade codecov tox
+
+    - name: Run tox targets for ${{ matrix.python-version }}
+      run: |
+        ENV_PREFIX=$(tr -C -d "0-9" <<< "${{ matrix.python-version }}")
+        TOXENV=$(tox --listenvs | grep "^py$ENV_PREFIX" | tr '\n' ',') tox
+
+    - name: Run extra tox targets
+      if: ${{ matrix.python-version == '3.9' }}
+      run: |
+        python setup.py bdist_wheel
+        rm -r djangorestframework.egg-info  # see #6139
+        tox -e base,dist,docs
+        tox -e dist --installpkg ./dist/djangorestframework-*.whl
+
+    - name: Upload coverage
+      run: |
+        codecov -e TOXENV,DJANGO

.travis.yml

@@ -49,3 +49,21 @@ commands = mkdocs build
 deps =
        -rrequirements/requirements-testing.txt
        -rrequirements/requirements-documentation.txt
+
+[testenv:py36-django32]
+ignore_outcome = true
+
+[testenv:py37-django32]
+ignore_outcome = true
+
+[testenv:py38-django32]
+ignore_outcome = true
+
+[testenv:py39-django32]
+ignore_outcome = true
+
+[testenv:py38-djangomain]
+ignore_outcome = true
+
+[testenv:py39-djangomain]
+ignore_outcome = true