Add lint to a workflow

Author: thombashi

.github/workflows/tests.yml

@@ -1,4 +1,4 @@
-name: Tests
+name: Run lint and tests
 
 on:
   pull_request:
@@ -21,5 +21,8 @@ jobs:
       - name: Setup
         run: make setup
 
+      - name: Run lint
+        run: make lint
+
       - name: Run tests
         run: make test