Feature/edit metadata authorization

I assume that pds_handle contain user group name(s) and thus we don't need to add roles. To reflect this I added customized method "groups" to user model. If the assumption is incorrect I will fix it and edit roles file.

@ekate So as discussed this would actually be something like 

    gis_cataloger:
       jsXX

Since that is the username for the fake user. Also, I think you should add these to the development and staging role mapper and add that same sample user in there to see if you can get this desired functionality not just in cucumber but in the application in other environments.