async (motorengine)

I'm trying to get a stack of `Sanic`, `mongodb` and `graphql` to work. All async..
I can do mongo async using https://github.com/heynemann/motorengine, but then I have no way of using `graphene-mongo` as it wants a valid `Mongoengine Model`.

I can't find any issues on this in this repo, so I might be getting this wrong, but is there plans for supporting async? Or anyway I can hack it in using the current `graphene-mongo`?