Add buildspec for minimal build

.github/workflows/pythonpackage.yml

@@ -3,8 +3,7 @@ name: Python package
 on: [push]
 
 jobs:
-  build:
-
+  build-all:
     runs-on: ubuntu-16.04
     strategy:
       max-parallel: 4
@@ -43,3 +42,32 @@ jobs:
       run: |
         pip install pytest
         pytest
+
+  build-tiny:
+    runs-on: ubuntu-16.04
+    strategy:
+      max-parallel: 4
+      matrix:
+        python-version: [3.6, 3.7]
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v1
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install .
+    - name: Lint with flake8
+      run: |
+        pip install flake8
+        # stop the build if there are Python syntax errors or undefined names
+        flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+        # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
+        flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+    - name: Test with pytest
+      run: |
+        pip install pytest
+        pytest