Make sure we have a tag or nothing (#28)

Author: Nyholm

.github/workflows/deploy-docker.yml

@@ -17,7 +17,7 @@ jobs:
 
       - name: Get the version
         id: get_version
-        run: echo ::set-output name=VERSION::${GITHUB_REF/refs\/tags\//}
+        run: echo ::set-output name=VERSION::${GITHUB_REF#refs/tags/}
 
       - name: Docker login
         run: echo '${{ secrets.DOCKER_PASSWORD }}' | docker login --username ${{ secrets.DOCKER_USERNAME }} --password-stdin