title: appium+protractor multiCapabilities for linux platform is possible?
body: <p>Their are 2 users having different roles:<br></p>
  
  <ol>
  <li>Doctor [login from pc web browser]</li>
  <li>Patient [login from android app]</li>
  </ol>
  
  <p>My protractor config file <br></p>
  
  <pre><code>multiCapabilities:[{
      browserName: 'android',
      platformName: 'android',
      platformVersion: '6.0',
      deviceName: 'android',
      autoWebview: true,
      app: '/home/myPc/e2e/build/android/patient.apk',
      autoGrantPermissions: 'true',
      framework: 'jasmine'
  },{
      browserName: 'chrome',
      platformName:'linux',
  }],
  </code></pre>
  
  <p>when i run test it througs error: Could not find a driver for platformName 'linux'</p>