LGTM. Thanks! (merged into master)

I have some comments though.

• Typo in https://github.com/Androbin/matrix-python-sdk/blob/99002f315425435fa84660ae391117dbdf805c2d/matrix_client/api.py#L197
• This warning in listen_for_events recommends to use _sync. However, starting your method name with an underscore is a common convention in Python to signal that this method is not part of the official API.

Other than that, looking good.

Oh, and to head off the question you will undoubtedly have: I would just drop the recommendation, but maybe @non-Jedi has something to say about that as well. The API is still beta and this is one of those places where it shines through.

Off the top of my head, it seems like we should just expose _sync as sync. Doesn't seem like something we necessarily need to put a ton of machinery in front of.

@Half-Shot: You have written a lot of this stuff and seem to have had a plan for deprecating initialsync. What do you think?