Use GitHub Actions to run mypy (#4594)

.github/workflows/tests.yml

@@ -62,6 +62,21 @@ jobs:
       - run: pip install -r requirements-tests-py3.txt
       - run: ./tests/pytype_test.py
 
+  mypy:
+    name: Run mypy against the stubs
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        platform: ["linux", "win32", "darwin"]
+      fail-fast: false
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: 3.8
+      - run: pip install -U git+git://github.com/python/mypy
+      - run: ./tests/mypy_test.py --platform=${{ matrix.platform }}
+
   mypy-self-test:
     name: Test mypy source with itself
     runs-on: ubuntu-latest

.travis.yml

@@ -1,20 +0,0 @@
-dist: bionic
-language: python
-python: 3.8
-
-jobs:
-  include:
-    - name: "mypy (typed-ast)"
-      python: 3.7
-      install: pip install -U git+git://github.com/python/mypy git+git://github.com/python/typed_ast
-      script: ./tests/mypy_test.py --platform=linux
-    - name: "mypy (ast)"
-      python: 3.8
-      install: pip install -U git+git://github.com/python/mypy
-      script: ./tests/mypy_test.py --platform=linux
-    - name: "mypy (Windows)"
-      install: pip install -U git+git://github.com/python/mypy
-      script: ./tests/mypy_test.py --platform=win32
-    - name: "mypy (Darwin)"
-      install: pip install -U git+git://github.com/python/mypy
-      script: ./tests/mypy_test.py --platform=darwin