[#7] Added remaining method to retrieve activity sessions for a sport, Added api helper module
Code refactor, following JohnPapa's AngularJS Style guide, added activitySessions related javascript
Refactored naming convention of modules, routing
Refactor: Controller As syntax, activate functions, moving api into services instead of components
Refactored routes to use a controller data factory, applied for activities
Refactor: Renamed Services into Utilities (They are reusable cross-project code blocks)
Added logger utility
Added Core module and Exception Modules