Simplify

.github/workflows/build.yml

@@ -7,14 +7,11 @@ jobs:
   extras:
     # Run coverage and extra tests only once
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        python-version: [3.7]
     steps:
       - uses: actions/checkout@v1
       - uses: actions/setup-python@v1
         with:
-          python-version: ${{ matrix.python-version }}
+          python-version: 3.7
       - run: make install
       - run: make test
       - run: make test-dist