Pinned github actions

.github/workflows/dockerhub.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Check out the repo
-        uses: actions/checkout@v2
+        uses: actions/checkout@ec3a7ce113134d7a93b817d10a8272cb61118579
 
       - name: Log in to Docker Hub
         if: github.event_name != 'pull_request'
@@ -22,7 +22,7 @@ jobs:
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
-        uses: docker/metadata-action@v3
+        uses: docker/metadata-action@e5622373a38e60fb6d795a4421e56882f2d7a681
         with:
           images: krateng/maloja
           # generate Docker tags based on the following events/attributes
@@ -32,7 +32,7 @@ jobs:
             latest=true
 
       - name: Build and push Docker image
-        uses: docker/build-push-action@v2
+        uses: docker/build-push-action@7f9d37fa544684fb73bfe4835ed7214c255ce02b
         with:
           context: .
           push: ${{ github.event_name != 'pull_request' }}
@@ -40,7 +40,7 @@ jobs:
           labels: ${{ steps.meta.outputs.labels }}
 
       - name: Update Readme and short description
-        uses: peter-evans/dockerhub-description@v2
+        uses: peter-evans/dockerhub-description@616d1b63e806b630b975af3b4fe3304307b20f40
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_PASSWORD }}