Properly display humidity

The Dark Sky API returns humidity as a double between 0.0 and 1.0, but
the UI expects a double between 0.0 and 100.0, so multiply Dark Sky's
value by 100.
Only fix date when dealing with Bucknell's weather service

The date does not need to be fixed when dealing with the Dark Sky API.
Automatically bump build number when building

Thanks to [1] for inspiration, as well as [2] for providing an agvtool
option.

  [1] https://gist.github.com/sekati/3172554
  [2] https://developer.apple.com/library/ios/qa/qa1827/_index.html