text: Title: Add "me" query
  Body: It would be useful to have a "me" query where the client gets the details of the logged-in user (sending a JWT). The client doesn't have to store the ID in that case.
  
  This could be done with something like this I think:
  
  ``` 
  def resolve_me(self, info):
    user = info.context.user
    if user.is_anonymous:
      raise GraphQLError('Not logged in!')
  ```
  
  What do you think?
  