git pull --rebase origin master

git push -u origin master

 ! [rejected]        master -> master (non-fast-forward)

error: failed to push some refs to

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.

git pull origin master --allow-unrelated-histories