Add CI

Author: collimarco

.github/workflows/ci.yml

@@ -0,0 +1,13 @@
+name: CI
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+    - name: Validate OpenAPI specification
+      run: make lint