向github push时免去输入用户名及密码

1 git config --global credential.helper store
2 下一次push时输入一次用户名密码
3 之后每次都可以自动push

$ git config --help查看这个选项信息

   credential.helper
       Specify an external helper to be called when a username or password credential is needed; the helper may consult
       external storage to avoid prompting the user for the credentials. Note that multiple helpers may be defined. See
       gitcredentials(7) for details.