Updated HomeBrew Recipe for next homebrew release

Belongs to magicmonty#276

Author: magicmonty

bash-git-prompt.rb

@@ -20,6 +20,7 @@ def caveats; <<-EOS.undent
     You should add the following to your .bashrc (or equivalent):
       if [ -f "$(brew --prefix bash-git-prompt)/share/gitprompt.sh" ]; then
         GIT_PROMPT_THEME=Default
+        __GIT_PROMPT_DIR=$(brew --prefix)/opt/bash-git-prompt/share
         source "$(brew --prefix bash-git-prompt)/share/gitprompt.sh"
       fi
     EOS