Fix finding git issue....

Fix finding git issue. http://stackoverflow.com/questions/592620/check-if-a-program-exists-from-a-bash-script

tools/install.sh

@@ -5,13 +5,10 @@ then
 fi
 
 echo "\033[0;34mCloning Oh My Zsh...\033[0m"
-which git > /dev/null
-if [[ $? -eq 0 ]]; then
-  /usr/bin/env git clone https://github.com/robbyrussell/oh-my-zsh.git ~/.oh-my-zsh
-else
+hash git >/dev/null && /usr/bin/env git clone https://github.com/robbyrussell/oh-my-zsh.git ~/.oh-my-zsh || {
   echo "git not installed"
   exit
-fi
+}
 
 echo "\033[0;34mLooking for an existing zsh config...\033[0m"
 if [ -f ~/.zshrc ] || [ -h ~/.zshrc ]