Implement notifications from Khan Academy to Glass

[ThibaudLopez]

We can either pull data from Khan Academy at a certain frequency (say every couple of seconds) and sift through the data for a particular event we're interested in (student is struggling), or we can (preferably) have Khan Academy push notifications to Glass when a particular event happens.

Right now, for the hackaton we only implemented the former, and the pull happens only once at startup (very much incomplete code). So we need to implement a loop to pull at a certain frequency.