add GitHub Actions CI with multiple Python versions

.github/workflows/ci.yml

@@ -0,0 +1,35 @@
+name: Python CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ '*' ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ['3.6', '3.7', '3.8', '3.9']
+
+    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
+        python -m pip install pygments nose websocket-client requests
+        pip install -r flake8-requirements.txt
+    - name: Lint with flake8
+      run: |
+        flake8 . --config setup.cfg
+    - name: Test with nose
+      run: |
+        ./setup.py nosetests
+    - name: Build
+      run: |
+        ./setup.py egg_info -Db '' sdist bdist_egg