Shiva API

 * supported resources (see https://github.com/tooxie/shiva-server#resources)
   * tracks, track, albums, album, artists, artist
 * fulltree parameter for album(s) and artist(s) resources
 * artist and album parameter for tracks resource
 * NOT INCLUDED: lyrics, shows

 * add travis support
 * tests for classes (Mapper, Entities, BusinessLayer, Controller (only API and BaseController))
   * add creation of code coverage report
 * renaming from "Media" to "Music"
 * add README
 * fix license headers
 * empty tests are marked as skipped
   * fulltree for track and tracks resource