Update dotfiles to include hash check for brew

Removed previously as assumed association with the Brewfile dependency,
but its just a check for the hash of a previously installed brew
forumlae.

Issue: #12

bin/dotfiles

@@ -89,33 +89,31 @@ if type -P 'brew' &> /dev/null; then
 	# Upgrade Homebrew formulaes
 	brew upgrade
 
-	# Linking applications to ~/Applications
-	brew linkapps --local
-
 	# Install Homebrew formulae
 	# here check the hash as well
 	brews="${DIR}/opt/homebrew"
 
-	# update and upgrade all packages
-	brew update
-	brew upgrade
+	old_brew="$(cat '${DIR}/var/homebrew')"
+	new_brew="$(md5 "${brews}" | cut -d ' ' -f 4)"
+	if [[ $new_brew != $old_brew ]]; then
 
-	# store IFS within a temp variable
-	OIFS=$IFS
+		# store IFS within a temp variable
+		OIFS=$IFS
 
-	# set the separator to a carriage return & a new line break
-	# read in passed-in file and store as an array
-	IFS=$'\r\n' formulae=($(cat "${brews}"))
+		# set the separator to a carriage return & a new line break
+		# read in passed-in file and store as an array
+		IFS=$'\r\n' formulae=($(cat "${brews}"))
 
-	for index in ${!formulae[*]}
-	do
-		# Test whether a Homebrew formula is already installed
-		if ! brew list '${formulae[$index]}' &> /dev/null; then
-			brew install '${formulae[$index]}'
-		fi
-	done
+		for index in ${!formulae[*]}
+		do
+			# Test whether a Homebrew formula is already installed
+			if ! brew list '${formulae[$index]}' &> /dev/null; then
+				brew install '${formulae[$index]}'
+			fi
+		done
 
-	IFS=$OIFS
+		IFS=$OIFS
+	fi
 
 	brew cleanup