consistent formatting in app.js
adding api key to user authentication
adding Trip model to survey side with a one-to-many relationship with Respondants.
creating unsubmitted trip list view and maps view. updating 'resume' strategy so that the trips are resumed (and not simply respondents).
fixing an issue in which resuming a trip at the point of event completion (in complete.js) resulted in app.currentTrip not being populated
fixing bug in which currentRespondent was not updated if Resume Trip sends user to complete.js (in between completed respondents)
improving the way currentRespondent and currentTrip are populated in complete.js (improving on the last 2 commits)