my issue was that the git client was too old
I'm using jenkins + git scm plugin to clone my git repo and I got the error
stderr: error: The requested URL returned error: 403 Forbidden while accessing https://github.com/owner/repo.git/info/refs
I opened the link with my error and I saw the message:
Please upgrade your git client. GitHub.com no longer supports git over dumb-http: https://github.com/blog/809-git-dumb-http-transport-to-be-turned-off-in-90-days
I have centos 6.5 and when I tried to update my git client I got from the yum repositories only the git client version 1.7.1
so in order to get the latest git client (for me it was 2.4.4) I had to use this guide
*there are many guides on the internet for this
and than I could clone my git repo successfully