new: GH workflow

.github/workflows/nosetests.yml

@@ -0,0 +1,35 @@
+name: Python application
+
+on: [push]
+
+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: Initialize submodules
+      run: git submodule update --init --recursive
+
+    - name: Install system dependencies
+      run: |
+        sudo apt install jq moreutils
+
+    - name: Install Python dependencies
+      run: |
+        python -m pip install --upgrade jsonschema
+
+    - name: Test
+      run: |
+        ./validate_all.sh