feat(track): Add track and populate it with search results

Create `wwTrack` directive
Create `.track` card and style it

[#2]
Merge remote-tracking branch 'origin/master' into feat-2-track
feat(duration-filter): Add duration filter

Filter duration of tracks
Add docs and unit tests

[#4]
Merge remote-tracking branch 'origin/master' into feat-2-track
feat(track): Highlight selected track temporarily
Merge pull request #39 from ilyakam/feat-2-track

Add track and populate it with search results