RtNotificationsTest.java:46-47: Create a test...

The puzzle `920-14172983` from #920 has to be resolved:

https://github.com/jcabi/jcabi-github/blob/b993b7ca546f94235452b942c7d119ba83843ff4/src/test/java/com/jcabi/github/RtNotificationsTest.java#L46-L47

The puzzle was created by Piotr Pradzynski on 10-Oct-15.

Estimate: 30 minutes,

If you have any technical questions, don't ask me, submit new tickets instead. The task will be \"done\" when the problem is fixed and the text of the puzzle is _removed_ from the source code. Here is more about [PDD](http://www.yegor256.com/2009/03/04/pdd.html) and [about me](http://www.yegor256.com/2017/04/05/pdd-in-action.html).