enable github actions

Author: asottile

.appveyor.yml

@@ -0,0 +1,51 @@
+name: main
+
+on:
+  push:
+    branches: [master]
+    tags:
+  pull_request:
+
+jobs:
+  main:
+    strategy:
+      matrix:
+        include:
+        # linux
+        - os: ubuntu-latest
+          python: pypy-3.7
+          toxenv: py
+        - os: ubuntu-latest
+          python: 3.6
+          toxenv: py
+        - os: ubuntu-latest
+          python: 3.7
+          toxenv: py
+        - os: ubuntu-latest
+          python: 3.8
+          toxenv: py
+        - os: ubuntu-latest
+          python: 3.9
+          toxenv: py
+        # windows
+        - os: windows-latest
+          python: 3.6
+          toxenv: py
+        # misc
+        - os: ubuntu-latest
+          python: 3.9
+          toxenv: docs
+        - os: ubuntu-latest
+          python: 3.9
+          toxenv: linters
+        - os: ubuntu-latest
+          python: 3.9
+          toxenv: dogfood
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python }}
+    - run: pip install --upgrade setuptools pip tox virtualenv
+    - run: tox -e ${{ matrix.toxenv }}

.github/workflows/main.yml

@@ -3,6 +3,7 @@ repos:
 -   repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v2.3.0
     hooks:
+    -   id: check-yaml
     -   id: debug-statements
         exclude: ^tests/fixtures/example-code/invalid-syntax.py$
     -   id: end-of-file-fixer

.gitlab-ci.yml

@@ -1,3 +1,11 @@
+.. image:: https://github.com/PyCQA/flake8/workflows/main/badge.svg
+   :target: https://github.com/PyCQA/flake8/actions?query=workflow%3Amain
+   :alt: build status
+
+.. image:: https://results.pre-commit.ci/badge/github/PyCQA/flake8/master.svg
+   :target: https://results.pre-commit.ci/latest/github/PyCQA/flake8/master
+   :alt: pre-commit.ci status
+
 ========
  Flake8
 ========