Get a handle on exceptions being thrown

[aidan-casey]

Right now, while an exception is thrown, these are mostly managed by Guzzle and where they are manged by us simply limited to the default PHP exception class. I want to get away from this and give useful errors to the developer by implementing several exception classes in the support folder.

We may want to look at the Guzzle side of things for this when dealing with #22 as well.