github: new check for MAVSDK tester Python scripts

.github/workflows/python_checks.yml

@@ -0,0 +1,23 @@
+name: Python CI checks
+
+on:
+  push:
+    branches:
+    - 'master'
+  pull_request:
+    branches:
+    - '*'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+      with:
+        token: ${{ secrets.ACCESS_TOKEN }}
+    - name: Install tools
+      run: sudo apt-get install python-setuptools flake8 mypy -y
+    - name: Check MAVSDK test scripts with mypy
+      run: mypy --strict test/mavsdk_tests/*.py
+    - name: Check MAVSDK test scripts with flake8
+      run: flake8 test/mavsdk_tests/*.py