Get branch name on branch delete github actions

on_delete.yml

name: Serverless Delete example

on:
  delete:
    branches:
      - actions-**

# Specify what jobs to run
jobs:
  deploy:
    name: delete
    runs-on: ubuntu-latest
    env:
      AWS_ACCESS_KEY_ID: ${{ secrets.AWS_ACCESS_KEY_ID }}
      AWS_SECRET_ACCESS_KEY: ${{ secrets.AWS_SECRET_ACCESS_KEY }}

    steps:
      - uses: actions/checkout@v1 

      - name: Github context
        run: echo "${{ toJson(github) }}"
      
      - name: Set Branch name
        run: |
          BRANCH=$(cat ${{ github.event_path }} | jq --raw-output '.ref')
          echo "${{ github.repository }} has ${BRANCH} branch"
          echo "::set-env name=STAGE::$(echo ${BRANCH})"

      - name: Echo Branch name
        run: echo Deleting from STAGE:$STAGE

      # Install npm and it's dependencies
      - name: npm install dependencies
        run: npm install

      # sls remove
      - name: Serverless
        uses: serverless/github-action@v1.53.0
        with:
          args: remove