Upgrade for CERT UNLP NGEN project

[rubiodamian]

Hi, i'm Damian Rubio from UNLP CERT, an academic CERT from the National university of La Plata, Argentina. We were using a custom rdap client, developed by me years ago. one month a go a saw your repository and it was so much better than our approach to rdap. So i made a mix between both projects and now we are using it on our NGEN project. This is a PR of all changes i made this las time, some changes are bug fixes but some of them may be related with our context as cert. So, i hope this work we did from Argentina will be useful to you.