For custom requests Gmail.client only gets set once a request is made 

I'm trying to do a few custom requests, however, unless a previous request is made (eg Gmail::Message.all) it errors out with "NoMethodError: undefined method `execute' for nil:NilClass"

Here's an example
https://gist.github.com/rserna2010/48b25ed2ac8a00cc039c

Also attempting to set the client field results in "NoMethodError: undefined method `client=' for Gmail:Module"
