Gpii 1029

http://issues.gpii.net/browse/GPII-1029
Note that we're now using proper rest semantics for the preferences server. This means that for creating new tokens, you should use POST (and with the /preferences URL without a token) and for updating existing preferences sets, you should use PUT (with the /preferences/<token> url) -- see https://github.com/GPII/universal/blob/master/documentation/PreferencesServer.md for details