cancelAllOperation fails with variable paths

the contract in AFNetworking's cancelAllHTTPOperationsWithMethod requires the pass of a path for a specific url e.g. "/projects/1" in order for it to cancel.

Because we can have variable paths ("/login, /logout, /projects/1") we can not satisfy this requirement.

Probably an overridden method is required to cancel all requests regardless of the path (as in our spec)