to avoid this merge branch 'master' notification (like in the subject), before pushing to remote repository, the developer has to synch with remote repo and rebase the local copy, command:

git pull --ff --rebase origin

The notification is done when the local commit is older than the last commit from the remote repository, or the remote has newer commits since local copy was pulled.

It is safe to run the command always before pushing, no matter the sync state between local and remote.

Cheers, Daniel