#8 Improved tests.

 - Added missing Task tests.

 - Added missing waveform retrieval client tests.

 - Removed unused PowerMockito dependency.

 - Import statics in tests.

 - Use Mockito annotations for mocks.

 - TODO: Still missing controller & gesture recognition tests.
Enabled lint checks in build.

 - Added min & target sdk

 - Allow backup

 - Fix ellipsis character
Add client credentials.

 - N.B. THIS IS BAD PRACTICE - Only doing it to make checkout easier.
Switched to non-expiring tokens.
#2 Added wall icon created by: http://www.webdesignerdepot.com
Remove caught exception stack trace output.
Fix bug in track equality check.
Specify reasoning on attribute encapsulation.
#3 Animate waveform from right to left.