問題描述：
Updates were rejected because the tip of your current branch is behind
情景：
在github或coding上創建項目，然后本地git init
然后沒有git pull -f --all
導致github上的版本里有readme文件和本地版本沖突，下面給出沖突原因：
[master][~/Downloads/ios] git push -u origin master
Username for 'https://github.com': shiren1118
Password for 'https://shiren1118@github.com':
To https://github.com/shiren1118/iOS_code_agile.git
! [rejected] master -> master (non-fast-forward)
error: failed to push some refs to 'https://github.com/shiren1118/iOS_code_agile.git'
hint: Updates were rejected because the tip of your current branch is behind
hint: its remote counterpart. Merge the remote changes (e.g. 'git pull')
hint: before pushing again.
hint: See the 'Note about fast-forwards' in 'git push --help' for details.
查看大部分資料，只有這個有用
http://www.cnblogs.com/xwdreamer/archive/2012/05/29/2523958.html
勾選強制覆蓋已有的分支（可能會丟失改動），再點擊上傳，上傳成功。
只有這句是核心，所以，本人就略微想了一下
[master][~/Downloads/ios] git push -u origin master -f
原文地址：https://blog.csdn.net/shiren1118/article/details/7761203