[CI] Add licence header check

.github/workflows/style.yml

@@ -34,3 +34,29 @@ jobs:
           black_args: "--line-length=120"
           flake8: true
           flake8_args: "--max-line-length=120"
+
+  check-license:
+    name: Check for License headers
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Check out Git repository
+        uses: actions/checkout@v2
+
+      - name: Install Python dependencies
+        run: pip install licenseheaders
+
+      - name: Download template file
+        run: wget https://raw.githubusercontent.com/johann-petrak/licenseheaders/master/templates/apache-2.tmpl
+
+      - name: Run check
+        run: |
+          licenseheaders -t apache-2.tmpl -y $YEARS -o $OWNER -n MLonMCU -u $URL -d . -E $EXTENSIONS
+          test -z "$(git status --untracked-files=no --porcelain)" || (echo "Please check your license headers!" ; false) && echo "License check was successful."
+        env:
+          OWNER: "TUM Department of Electrical and Computer Engineering"
+          PROJECT: "MLonMCU"
+          YEARS: "2022"
+          URL: "https://github.com/tum-ei-eda/mlonmcu.git"
+          EXTENSIONS: "py c cpp"
+          EXCLUDE: ".venv models"