Downgraded to PHPUnit 3.7 so I can use the PHPStorm interface. Will upgrade when PHPStorm supports 4.1.
Removed `singleton()` methods from both `Card` and `PayXML`
Added new `Request` class. Replaces old `PayXML->curl()` method.
`Request` class is now passed into `PayXML` constructor - Makes testing easier.
Added mocks for `Request` testing. Will move them to their own class at some point.
Testing is now faster and more complete.