github asking for credentials during git push

credentials.log

~$ git clone https://github.com/tetalab/deux-mille.git
Cloning into 'deux-mille'...
remote: Counting objects: 6, done.
remote: Compressing objects: 100% (4/4), done.
remote: Total 6 (delta 0), reused 6 (delta 0)
Unpacking objects: 100% (6/6), done.
~$ cd deux-mille/
deux-mille (master)$ cp ../code/deux-mille/index.html .
deux-mille (master)$ gco "remove unused html"
[master 89b27d0] remove unused html
 1 file changed, 55 insertions(+), 165 deletions(-)
 rewrite index.html (65%)
deux-mille (master)$ git push
Username for 'https://github.com': ^C
deux-mille (master)$ 

https://help.github.com/articles/why-is-git-always-asking-for-my-password