title: Github Action : rsync setup keeps on failing
body: <p>I have a workflow as <code>deployment.yml</code> which looks like this:</p>
  <pre><code>name: Deployment
  
  on:
    push:
      branches: [ production ]
  
  jobs:
    deploy:
      runs-on: ubuntu-latest
  
      steps:
      - uses: actions/checkout@v2
  
      - uses: actions/setup-node@v1.1.0
        with:
          version: 10.x
  
      - name: Install dependencies
        run: |
          composer install -o
          yarn
      - name: Build
        run: yarn build:production
      
      - name: Sync
        env:
          dest: 'user@server:/var/www/html/wp-content/themes/theme-name'
        run: |
          echo &quot;${{secrets.DEPLOY_KEY}}&quot; &gt; deploy_key
          chmod 600 ./deploy_key
          rsync -chav --delete \
            -e 'ssh -i ./deploy_key -o StrictHostKeyChecking=no' \
            --exclude /deploy_key \
            --exclude /.git/ \
            --exclude /.github/ \
            --exclude /node_modules/ \
            ./ ${{env.dest}}
  </code></pre>
  <p>When this action executes I get an error at <code>Sync</code> step with the following error.</p>
  <pre><code>Run echo &quot;***&quot; &gt; deploy_key
    echo &quot;***&quot; &gt; deploy_key
    chmod 600 ./deploy_key
    rsync -chav --delete \
      -e 'ssh -i ./deploy_key -o StrictHostKeyChecking=no' \
      --exclude /deploy_key \
      --exclude /.git/ \
      --exclude /.github/ \
      --exclude /node_modules/ \
      ./ root@111.11.111.111:/var/www/html/wp-content/themes/theme-name
    shell: /bin/bash -e {0}
    env:
      dest: root@159.89.165.152:/var/www/html/wp-content/themes/theme-name
  Warning: Permanently added '111.11.111.111' (ECDSA) to the list of known hosts.
  Load key &quot;./deploy_key&quot;: invalid format
  Permission denied, please try again.
  Permission denied, please try again.
  root@111.11.111.111: Permission denied (publickey,password).
  rsync: connection unexpectedly closed (0 bytes received so far) [sender]
  rsync error: unexplained error (code 255) at io.c(235) [sender=3.1.2]
  ##[error]Process completed with exit code 255.
  </code></pre>
  <p>This is a Digital Ocean droplet with SSH key set and added to Authorized keys.
  Also inside me repository setting
  I added them to:</p>
  <ol>
  <li>Deploy Keys : as DEPLOY_KEY</li>
  <li>Secrets : as DEPLOY_KEY [I added this because earlier in the error area Deploy keys output was blank.]</li>
  </ol>
  <p>Is my setup wrong?</p>