* MediaDetailFragment: add zoom feature
* fragment_media_detail: add SimpleDrawee for Scroll picture
* ZoomableActivity: activity which facilitates zoom in
* activity_zoomable: xml for zoom activity
* zoomControllers: controllers for handling gesture and zooming
* MediaDetailFragment: fixing name of image variable
* MediaDetailFragment: display as per the aspect ratio of image
* add zoom activity to AndroidManifest
* fix travis ci faliure
* fix resizing of image
