Add conditional for release (#104)

Author: martialonline

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ env:
 jobs:
 
   build:
-    name: Build Artifacts
+    name: Build Image
     runs-on: ubuntu-latest
     steps:
       - name: Checkout Repository
@@ -35,18 +35,18 @@ jobs:
           tag_with_sha: true
           push: false
 
-  publish:
-    name: Publish Artifacts
+  release:
+    name: Release Image
     runs-on: ubuntu-latest
     needs: build
-    if: github.event_name == 'create' && contains(github.ref, 'refs/tags/')
+    if: github.ref == 'refs/heads/master' && github.event_name == 'create' && contains(github.ref, 'refs/tags/')
     steps:
       - name: Checkout Repository
         uses: actions/checkout@v2
       - name: Retrieve Tag
         id: get_version
         run: echo ::set-output name=GIT_TAG::$(echo ${GITHUB_REF/refs\/tags\//} | tr -d v)
-      - name: Push Image
+      - name: Push to Dockerhub
         uses: docker/build-push-action@v1
         with:
           repository: nginx/nginx-prometheus-exporter