Support renaming git repository

[peerchemist]

Git repositories can be renamed, and git itself support seamless integration of renamed repository with old name.

https://github.com/blog/1508-repository-redirects-are-here

Will this break integration with peer4commit?

[sigmike]

After you rename the repository you must update the "GitHub URL" in the project settings because the GitHub API doesn't redirect.

Other than that everything should work fine.

Let me know if you have any issue.