Edit repsitories

[cassidyjames]

It might be useful to be able to edit a repository, i.e. switching to a different release name when a vendor doesn't support the current base release.

[mirkobrombin]

Good idea. I will see how to develop it thanks.

[mirkobrombin]

I will add this here:
https://github.com/linuxhubit/ppaextender#todo