[BUG] Add repo command may present an incomprehensible error

[brunasilvazup]

What happened:
When a url that does not exist in the domain or an access with the wrong credential is displayed, the error that is presented is the reported html.

What you expected to happen:
An error indicating that the url in the domain could not be found.

How to reproduce it (as minimally and precisely as possible):
Execute rit add repo with:
? Select your provider: Gitlab
? Repository name: repo
Your repository "repo" is gonna be overwritten.
? Do you want to proceed? yes
? Repository URL: https://github.com/ZupIT/ritchie-formulas
? Is a private repository? no

And don't register a gitlab user.

Anything else we need to know?:

Environment:

• Ritchie version (use rit --version): 2.0.2
• Operating System: Ubuntu 18.04.4 LTS
• Network plugin / Tool and version (if this is a network-related / tool bug):
• Others: