Add Poor-man’s auth to Ratel UI

Moved from GitHub ratel/224

Posted by MichelDiz:

Reference: https://dgraph.io/docs/master/deploy/#dgraph-administration

Dgraph supports Poor-man’s auth. Which you can pass as an argument in the flag --auth_token.
For now, it protects Alter endpoint and some other admins operations, but in the future, it will protect mutations, queries, and GraphQl queries.

BTW, the flag mention “token” but you can literally use any Htpasswd Generator out there, also as it is just a string, you can pass any phrase or combination you want. I would strongly recommend a Htpasswd Generator or something safer like a “hash/Bcrypt”.

Addressed by
https://github.com/dgraph-io/ratel/pull/248