Put /usr/local/bin in front of /usr/bin in PATH

Homebrew uses /usr/local/bin for storing binaries. To make sure brew-installed
binaries are ran instead of natively installed ones (existing in /usr/bin), make
sure the system searches /usr/local/bin first.
Merge branch 'master' of github.com:sindrenm/dotfiles

Conflicts:
	zsh/config/environment.zsh