simplify version switching

[dancrew32]

First off, thanks for the module! Just have a quick suggestion for the project:

Looks like this could use some more-obvious API version switching documentation.

Didn't know url= kwarg was available until I read through https://github.com/kurttheviking/python-simple-hipchat/blob/master/hipchat/__init__.py#L7 and saw https://github.com/kurttheviking/python-simple-hipchat/blob/master/hipchat/__init__.py#L12-L13

Since there's a V2 API now, might be worth documenting hipchat.HipChat(method=.., url=..) and the constructor might be simplified by just making it hipchat.HipChat(method=..., version=2)

[kurttheviking]

@dancrew32 thank you; i wasn't aware of the v2 api until recently but putting in simple version switching seems to make the most sense

[kurttheviking]

@dancrew32 I've talked to others who are looking for a similar feature so this is something I will look into this weekend or early next week; if you happen to have a PR I'd be happy to take a look and speed things along