Start migrating CI to GitHub actions

Phase out travis-ci which is not owned by a single account.

Author: ywangd

.github/workflows/python-package.yml

@@ -0,0 +1,42 @@
+# This workflow will install Python dependencies, run tests and lint with a variety of Python versions
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions
+
+name: Python package
+
+on:
+  push:
+    branches: [ master, dev ]
+  pull_request:
+    branches: [ master, dev ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [2.7, 3.6, 3.8]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install --upgrade flake8>=3.7.9 pyparsing==2.4.4 pytest==4.6.6
+    - name: Lint with flake8
+      run: |
+        # 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.
+        flake8 . --count --exit-zero --max-complexity=10 --max-line-length=88 --statistics
+        # show pytest version
+        py.test --version
+        # install
+        pip install ".[testing]"
+    - name: Test with pytest
+      run: |
+        pytest tests/ --ignore=tests/system/data/ --showlocals --verbose --show-capture=all --log-level=debug