Fixed azenk/smoker-client#4

Two problems:
* Google was being redirected to the dev instance of the api.
* When a user refuses to give us permission to access their data,
	no parameters are passed to the callback.  This was causing a server
	error due to the fact that the parameters had no defaults assigned.
	I assigned the defaults to be null, then added a check for this.
	Users who refuse to give permission will be safely redirected back
	to the client.