Add GitHub actions

.github/workflows/python_tests.yml

@@ -0,0 +1,36 @@
+name: Python tests
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        platform: [ubuntu-latest, macos-latest, windows-latest]
+        python-version: [3.6, 3.7, 3.8]
+
+    runs-on: ${{ matrix.platform }}
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - 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 -r requirements.txt
+        pip install -r requirements-test.txt
+        pip install .
+
+    - name: Test with pytest
+      run: |
+        pytest --cov --verbose

requirements-test.txt

@@ -1,4 +1,4 @@
-pytest==3.9.2
+pytest>=4.6
 codecov
 pytest-cov
 pytest-sugar