Tweaked actions config

Author: GrahamCampbell

.github/workflows/checks.yml

@@ -54,3 +54,14 @@ jobs:
 
       - name: Execute Psalm
         run: vendor/bin/psalm --no-progress --output-format=github
+
+  bccheck:
+    name: BC Check
+    runs-on: ubuntu-20.04
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Execute BC Check
+        uses: docker://nyholm/roave-bc-check-ga