如何解决failed to push some refs to git,如何解决网络拥堵

Administrator@PC-20150110FGWU /K/cocos2d/yc (master) $ git push -u origin master To git@github.com:yangchao0718/cocos2d.git ! [rejected] master -> master (non-fast-forward) error: failed to push some refs to 'git@github.com:yangchao0718/cocos2d.git hint: Updates were rejected because the tip of your current branch is behin hint: its remote counterpart. Integrate the remote changes (e.g. hint: 'git pull ...') before pushing again. hint: See the 'Note about fast-forwards' in 'git push --help' for details.