Support for multiple Gmail accounts

[psresnik]

Thanks for this great package! I am looking for an easy way to use simplegmail with multiple accounts. A very simple modification would seem to be the ability to pass the credentials file as an argument when initializing the Gmail class, rather than hard-wiring. (My alternative work-around would be to have my program actually run in separate account-specific directories but that seems rather kludgy.) Might it be possible to add this?

[Benji-create]

this would be awesome