Your local branch doensn't know about the remote branch. If you don't tell git that your local branch (master) is supposed to compare itself to the remote counterpart (origin/master in this case); then git status won't tell you the difference between your branch and the remote one. So you should use:
git branch --set-upstream-to origin/master
or with the short option:
git branch -u origin/master
This options --set-upstream-to (or -u in short) was introduced in git 1.8.0.
Once you have set this option; git status
will show you something like:
# Your branch is ahead of 'origin/master' by 1 commit.