Add 'user' fetch functionality to api client
leaving the door open for other user manipulation in the future.
Also, fixed a test in system (list_users) where the final test wasn't actually confirming size of result-set
(this test will now fail if the jenkins has <> 1 user)
Forgot to change the name on new file :)
Update unit tests to match correct jenkins user url
Add new files to gemspec
Rename user class methods to remove the 'user' in them...  Add dep warning to System#list_users... Adjust tests to just check for return type in user listing methods (to avoid strange behavior if size changes
Renamed methods, didn't rename test descriptions
Merge pull request #98 from maestrodev/user

Add (basic) User retrieval subclass