Added async http client library and dependancy
Added APIManager singleton
Fixed gradle issues and added get stories call
Added internet permission
Refactored response handler and replaced topics with stories type
Added thumbnail string and removed id
Added create from method
Removed adapter constructor and added set objects method
Replaced summary references with description and added list updating after API call
Merge branch 'app-feature/async-http-client' into app
Added cache manager class
Added load/save and exists/modified date methods
Added stories caching
Added cache loading for stories list
Added file age checking
Merge branch 'app-feature/caching' into app

* app-feature/caching:
  Added file age checking
  Added cache loading for stories list
  Added stories caching
  Added load/save and exists/modified date methods
  Added cache manager class
Replaced story details view with webview
Fixed issue with caching check not triggering api refresh
Set URL to load
Enabled javascript for webview
Override url loading to prevent opening external web browser