title: Parse Server: REST-API-Key Authentication does not work
body: <p>I configured my parse server as following:</p>
  
  <pre><code>var api = new ParseServer({
      databaseURI: databaseUri || 'mongodb://localhost:27017/dev',
      cloud: process.env.CLOUD_CODE_MAIN || __dirname + '/cloud/main.js',
      appId: process.env.APP_ID || 'XXXXXXXXXXXXXXX',
      clientKey: process.env.CLIENT_KEY || 'XXXXXXXXXXXXXXX',
      restAPIKey: process.env.RESTAPI_KEY || 'XXXXXXXXXXXXXXX',
      masterKey: process.env.MASTER_KEY || 'XXXXXXXXXXXXXXX', //Add your master key here. Keep it secret!
  
      ...
  
      serverURL: process.env.SERVER_URL || 'https://myserver.com:1337'  // Don't forget to change to https if needed
  });
  </code></pre>
  
  <p>Sending a push message with the master key specified works:</p>
  
  <pre><code>curl -X POST \
    -H "X-Parse-Application-Id: XXXXXXXXXXXXXXX" \
    -H "X-Parse-Master-Key: XXXXXXXXXXXXXXX" \
    -H "Content-Type: application/json" \
    -d '{
          "where": {
            "deviceType": {
              "$in": [
                "ios"
              ]
            }
          },
          "data": {
            "title": "The Shining",
            "alert": "All work and no play makes Jack a dull boy."
          }
        }'\   https://myserver.com/parse/push
  </code></pre>
  
  <p>However if I only provide the rest api key, it does not work.</p>
  
  <pre><code>curl -X POST \
    -H "X-Parse-Application-Id: XXXXXXXXXXXXXXX" \
    -H "X-Parse-REST-API-Key": XXXXXXXXXXXXXXX \
    -H "Content-Type: application/json" \
    -d '{
          "where": {
            "deviceType": {
              "$in": [
                "ios"
              ]
            }
          },
          "data": {
            "title": "The Shining",
            "alert": "All work and no play makes Jack a dull boy."
          }
        }'\   https://myserver.com/parse/push
  </code></pre>
  
  <p>What is wrong with my server configuration? I thought it should work with the rest API key as soon as I define it?</p>