Parses branch name and optionally maps to environment name

- uses: alexrogalskiy/github-actions/github-action-branch-mapper@master
  with:
    github-ref: ${{ github.ref }}
    map: ${{ toJSON({ dev: 'staging', production: 'production', '.*': 'sandbox' })  }}

Outputs:

• environment - environment name

Run locally:

• yarn run_action --action github-ref-to-env --github-ref refs/heads/my/branch-name --map '{ "dev": "staging", ".*": "sandbox" }'