Summary:
Moving files to `Common` dir so changes are more automated with Buck and easier to manage in the long run. Ran `pod install` on test and example targets. Updated buck file to include `Common` so diffing lib still works.
Part of #270
Reviewed By: jessesquires
Differential Revision: D4346722
fbshipit-source-id: 366d89f6dd571b158b5fccd542080c51517ed341
