disable pull request docker push

.github/workflows/dockerimage.yml

@@ -2,10 +2,7 @@ name: Docker Image CI
 
 on:
   push:
-    branches: 
-      - master
-  pull_request:
-    branches: 
+    branches:
       - master
 
 defaults:
@@ -18,11 +15,10 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v2
-    - uses: docker/build-push-action@v1
-      with:
-        username: ${{ secrets.DOCKER_USERNAME }}
-        password: ${{ secrets.DOCKER_PASSWORD }}
-        repository: kazhala/dotbare
-        tag_with_sha: true
-
+      - uses: actions/checkout@v2
+      - uses: docker/build-push-action@v1
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+          repository: kazhala/dotbare
+          tag_with_sha: true