Merge pull request #70 from kayteh/ci-prs

chore: make docker workflows always run, only push on master

.github/workflows/docker.yml

@@ -1,7 +1,4 @@
-on: 
-  push:
-    branches:
-      - master
+on: [push, pull_request]
 
 name: Docker Workflow
 
@@ -12,15 +9,17 @@ jobs:
     steps:
       - uses: actions/checkout@v1
 
-      - name: Docker Login
-        run: |
-          echo ${{ secrets.DOCKER_PASSWORD }} | docker login -u ${{ secrets.DOCKER_USERNAME }} --password-stdin
-  
       - name: Docker Build
         run: |
           docker build . -t katie/roleypoly:${{ github.sha }}
 
+      - name: Docker Login
+        if: github.ref == 'refs/heads/master'
+        run: |
+          echo ${{ secrets.DOCKER_PASSWORD }} | docker login -u ${{ secrets.DOCKER_USERNAME }} --password-stdin
+  
       - name: Docker Push
+        if: github.ref == 'refs/heads/master'
         run: | 
           docker push katie/roleypoly:${{ github.sha }}