Update flutter.yml

Author: NRijnberg

.github/workflows/flutter.yml

@@ -25,8 +25,11 @@ jobs:
       - name: Check code format
         run: dart format . -o none --set-exit-if-changed
 
+      - name: Run code generation
+        run: cd example && flutter pub get && flutter pub run build_runner build && cd ..
+
       - name: Analyze project source
         run: flutter analyze --fatal-infos
 
       - name: Run tests
-        run: flutter test
+        run: flutter test