Merge pull request SvanBoxel#25 from rosiel/tags

Use `$GITHUB_REF_NAME` to work with both branches and tags.

Author: SvanBoxel

entrypoint.sh

@@ -22,7 +22,7 @@ DEFAULT_POLL_TIMEOUT=10
 POLL_TIMEOUT=${POLL_TIMEOUT:-$DEFAULT_POLL_TIMEOUT}
 
 sh -c "git config --global --add safe.directory /github/workspace"
-git checkout "${GITHUB_REF:11}"
+git checkout "$GITHUB_REF_NAME"
 
 branch="$(git symbolic-ref --short HEAD)"
 branch_uri="$(urlencode ${branch})"