Add ability to get a single refund

1.3.1

Add method to get a single refund

Adds support for refunding payments

Credit to @MGMonge

Updated to work with Guzzle ~6.0

This release drops support for Guzzle ~5.0 in favour for ~6.0

1.1.2

Merge branch 'fyfey-redirect_flow'

1.1.1

Merge branch 'stephangroen-patch-1'

1.1.0

Merge pull request #12 from stephangroen/master

Authentication update for API version 2015-04-29

v1.0.0

Merge pull request #11 from fyfey/links

Added a links array in Entity which will automatically be filled