This implements the changes discussed in #202 to make it possible for all Pithub objects to check the current rate limit for whatever authentication method they are using.
Coverage decreased (-0.08%) to 98.995% when pulling c6e84c80b7f05ac84aced36828e031002fb1aa6d on jjatria:feat-rate-limit into 6ec66c3d8884bd98598e4c19c9e8f4908c09fdf4 on plu:master.
This implements the changes discussed in #202 to make it possible for all Pithub objects to check the current rate limit for whatever authentication method they are using.