updated code to support Paymill v2
fixing missing self in newclient function
setuptools packaged
fixed dependency
updateclient: wrong api endpoint
updateclient actually uses the clients endpoint, despite what the doc say (https://www.paymill.com/en-gb/documentation-3/reference/api-reference/index.html#update-client) but uses the PUT method
getcarddetails was broken, too
merged kliment's fork using requests
Merge pull request #3 from cruncher/master

Repackaged kliment's fork for setuptools and applied some pep8 love.