chore: update workflow

.github/workflows/action-test.yml

@@ -28,6 +28,14 @@ jobs:
           VERSION="${VERSION//v}"
           TAGS="${DOCKER_IMAGE}:${VERSION},${DOCKER_IMAGE}:${SHORTREF}"
 
+          # If the VERSION looks like a version number, assume that
+          # this is the most recent version of the image and also
+          # tag it 'latest'.
+          if [[ $VERSION =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
+            TAGS="$TAGS,${DOCKER_IMAGE}:latest"
+          fi
+
+
           # Set output parameters.
           echo ::set-output name=tags::${TAGS}
           echo ::set-output name=docker_image::${DOCKER_IMAGE}