Only upgrade bash and not the whole system

Running `apt-get upgrade` or `pacman -S` might cause a bunch of problems in packages which are completely unrelated to this bug. If you're going to give general advice, you should probably make the commands as specific as possible.
Don't install bash if not installed
remove pacman -u option
Merge pull request #8 from itsadok/patch-1

Only upgrade bash and not the whole system