Authenticate user when they are viewing a specific trip

[keiffer01]

Issue summary

Although users are checked to see if they are authenticated when they attempt to view a PrivateRoute page, it does not check to see if they have been listed as a collaborator when they view a specific trip's activities.

Expected behavior

User is checked to see if they are listed as a collaborator for a trip's activities. If they are, they can stay on the page. If not, they should be redirected to a page stating that they do not have the permission to view that trip, with the ability to return to their VIEW_TRIPS page.

Actual behavior

Any user can see any trip given the URL, regardless of whether or not they have been listed as a collaborator for it.