Update Ratel to use new HTTP API

Moved from GitHub ratel/87

Posted by MichelDiz:

Ref: https://github.com/dgraph-io/tutorial/issues/66

More details here Remove custom HTTP Headers, cleanup API by mangalaman93 · Pull Request #3365 · dgraph-io/dgraph · GitHub

Captura de Tela 2019-05-24 às 13 02 36

paulftw commented :

Fixed in master