Introduced Travis UX flow, abstract BuildsViewController

DRY'd up some code between the BuildsViewControllers
[#64632074]
DRY up DateFormatter parsing into a thread safe Helper method
Build now defines an abstract class method .fetch

To be implemented by all subclasses.
Client can list and save travis builds

[#64632074]
Update travis builds from backend
[Client] Fix Build#isSimilarTo
Merge branch 'travis'

[Finishes #64632074]