Git push 时出现问题：failed to push some refs to ‘github.com:userNamel/repositoryName.git‘

问题描述：Github上新建的一个带README等文件的仓库，第一次上传时，出现如下问题

 ! [rejected]        master -> master (non-fast-forward)
error: failed to push some refs to 'github.com:userNamel/JAVA_Learning.git'
hint: Updates were rejected because the tip of your current branch is behind
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.

解决方法：执行git pull --rebase github_origin master命令，知道本地仓库出现远程仓库已有的文件，再次执行git push github_origin master成功上传！