Init commit for spotify app.

Added boilerplate app with 3 tabs.
Added gruntfile with jshint for now.
gitignore update
app added as nonsubmodule
app: banner added.

now playing js file added.
toplist tab js added
search.js added.

banner updated: link now has black bg
Merge branch 'spotify-app-init' into spotify-app
search.js now fixed.

call to module in main.js was missing.
now.js: curArtistURI
jquery added.
related artists showcase.

shows list of related artists of current playing
artists.
styled grid
graph drawing with depth = 1. using visjs
Merge branch 'feature-nowplaying' into spotify-app
updated tabs view

manifest tabs replaced for the UI module.
grid layout removed.
Merge branch 'spotify-app'

First version of RAMA Spotify App
refactoring: ArtistGraph now handles graph stuff.

ArtistGraph should be initialized with init(artist, [options] ), where
artist is of type $api/models.Artist
Optional parameter options defines graph options.
After init, to draw the graph simply call drawGraph(element), where
element is of type DOM object.

Example:
        var currentArtist =
	models.Artist.fromURI(player.track.artists[0].uri);

	ArtistGraph
	  .init(currentArtist)
	  .drawGraph(self.element);
ArtistGraph evolved to a function.

Want to give a nickname to ArtistGraph?
refactoring for testing
refactoring for testing

testing with jasmine added.
travis yml file added.