remote.pull prints Already up-to-date.

The command print "Already up-to-date" to the console.

It seems that problem is the use of with_stdout=False that then does not both to do anything to stdout.

[git-python-with-stdout.txt](https://github.com/gitpython-developers/GitPython/files/275304/git-python-with-stdout.txt)

The attached patch seems to fix the problem by setting stdout to DEVNULL. Tested on python 3.4.
