Explicitly calling bash for check_for_upgrade
Explicitly calling bash for check_for_upgrade

Works on a mac with /usr/bin/sh since it is linked to bash. Does not work
without this fix on ubuntu and the script will fail with a syntax error.

kaihowl/dotfiles,kaihowl/dotfiles,kaihowl/dotfiles,kaihowl/dotfiles,kaihowl/dotfiles