upstream 에서 origin으로 바꾸기
$ git remote -v
upstream https://github.com/munhwas1140/serial-mock.git (fetch)
upstream https://github.com/munhwas1140/serial-mock.git (push)
$ git remote rename <원래 이름> <바꿀 이름>
$ git remote rename upstream origin
$ git remote -v
origin https://github.com/munhwas1140/serial-mock.git (fetch)
origin https://github.com/munhwas1140/serial-mock.git (push)