ADD support to other web git repos (gitlab etc)

[gdamdam]

At the moment the script is working only for web repo url from github.
We need to extend it to support other web git repos: gitlab, bitbucket, etc

[vxbinaca]

This was why I tried to streamline the identifier to just "github", because future naming schemes will have to either follow it or will inevitably drift from it.

But yes I agree, more support. Lemme see what I can do.

[zackbatist]

I replaced the api parameters with values published by gitlab in a fork: https://github.com/zackbatist/iagitup/tree/gitlab. I have not and do not intend to make this a user-selectable option, since my knowledge of python is somewhat limited. If you would like to work on this further, please start a development branch for this issue and I will merge my fork with it.