Adjusted buildAndPushImage.yml so dev branch is also an image

.github/workflows/buildAndPushImage.yml

@@ -2,12 +2,16 @@ name: buildAndPushImage
 
 on:
   push:
-    branches:    
+    branches:
       - 'main'
-
+      - 'dev'
+  pull_request:
+    branches:
+      - 'main'
+
 env:
   IMAGE_NAME: helm-plugin
-
+  IMAGE_TAG: ${{ github.ref == 'refs/heads/main' && 'latest' || 'testing' }}
 jobs:
   build-with-paketo-push-2-dockerhub:
     runs-on: ubuntu-latest
@@ -24,8 +28,8 @@ jobs:
 
       - name: Build app with pack CLI using Buildpack Cache image (see https://buildpacks.io/docs/app-developer-guide/using-cache-image/) & publish to Docker Hub
         run: |
-          pack build index.docker.io/well5a/$IMAGE_NAME:latest \
+          pack build index.docker.io/well5a/$IMAGE_NAME:$IMAGE_TAG \
               --builder paketobuildpacks/builder:base \
               --path . \
-              --cache-image index.docker.io/well5a/$IMAGE_NAME-paketo-cache-image:latest \
+              --cache-image index.docker.io/well5a/$IMAGE_NAME-paketo-cache-image:$IMAGE_TAG \
               --publish