switch database :useDb()

I have been exploring various libraries for mongoose and graphql and this really looks promising.Great work guys .

I have a scenario where i need to switch database on the bases of request parameters is there any way i can replace the model object for every resolver using [useDb](http://mongoosejs.com/docs/api.html#drivers_node-mongodb-native_connection_NativeConnection-useDb) function

I may be trying to find some thing which is already available in graphql-compose-mongoose