Add Sauce Labs configuration keys to strArgs

Right now you can't do something as follows because Sauce Labs configuration
options are not passed to protractor:

    options: {
      keepAlive: false,
      args: {
        sauceUser: 'habbostories',
        sauceKey: 'ca5d8c76-58e2-4124-b844-591c037764f1',
        baseUrl: 'https://s3.amazonaws.com/habbo-stories-staging/index.html',
        params: {
          loginURL: 'http://habbo-stories-api-staging.herokuapp.com/sessions/e2etest'
        }
      }
    }