Add support for Dgraph database

[joshhopkins]

What would you like to be added:

Dgraph query and monitoring support.

Why is this needed:

Dgraph is a great open source database.

[dprokop]

@joshhopkins thanks for your suggestion! We don't plan to add support for Dgraph at the moment, so I will close the issue for now. Let's see what the community interest is, and if this issue will be upvoted we will consider adding it in the future.

[ake-persson]

+1 support for dGraph

[LockedThread]

I second that there should be support for dgraph