Merge pull request #16 from iamseth/master

Fix for admin.users.add() method
Fix: response.status_code is an int not a string

Also added the response reason in the error message.
Updated client to reuse auth cookie
Merge pull request #18 from CedricSchmeits/master

Fix: response.status_code is an int not a string
Merge pull request #19 from DesktopMan/session

Updated client to reuse auth cookie
Support a user-supplied Requests Session
helpers.py: Ensure parameters are not overwritten when paging

When subsequent pages are requested, any request parameters were being overwritten. Instead, leave the parameters as is, and simply add in the start parameter in addition.
Merge pull request #20 from wjt/requests-auth

Support a user-supplied Requests Session
Merge pull request #22 from Cogito/patch-1

helpers.py: Ensure parameters are not overwritten when paging
Branches are a paginated resource, so they should be exposed like one