Add CI build settings

.github/workflows/ci-build.yml

@@ -0,0 +1,34 @@
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions
+name: CI Build
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    strategy:
+      matrix:
+        # TODO: 3.10 in GH Actions is not yet stable enough for us
+        # You may often encounter "Error: Process completed with exit code 250."
+        python-version: ['3.6', '3.9']
+    env:
+      PYTHON_SLACK_SDK_MOCK_SERVER_MODE: 'threading'
+      #CI_UNSTABLE_TESTS_SKIP_ENABLED: '1'
+    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: |
+        pip install -U pip wheel
+        pip install -e ".[testing]"
+        pip install -e ".[optional]"
+    - name: Run validation
+      run: |
+        python setup.py validate