brew: fail fast when not using bash
brew: fail fast when not using bash

nandub/brew,JCount/brew,Homebrew/brew,JCount/brew,MikeMcQuaid/brew,nandub/brew,MikeMcQuaid/brew,nandub/brew,EricFromCanada/brew,EricFromCanada/brew,nandub/brew,JCount/brew,Homebrew/brew,Homebrew/brew,EricFromCanada/brew,EricFromCanada/brew,MikeMcQuaid/brew,JCount/brew,MikeMcQuaid/brew,Homebrew/brew