Adjust PATH in non-interactive shells

The default git isn't necessarily on the system path. When committing
from a remote system, the default git doesn't recognize settings from
.gitconfig that require a newer version. Thus, we adjust PATH to include
at least *some* custom folders from .bashrc, even though it's generally
the job of .bash_profile to change environment variables.
Merge branch 'master' of github.com:rkennedy/dotfiles