check for nvm presence before using, survive abscence

server-ce/bin/install-services

@@ -4,12 +4,12 @@ grep 'name:' config/services.js | \
 	sed 's/.*name: "\(.*\)",/\1/' | \
 	while read service
 	do
-		pushd $service &&
-		echo "Installing Service $service" &&
-		echo '  installing Node' &&
-		nvm install &&
-		nvm use &&
-		echo '  installing Dependencies' &&
+		pushd $service
+		echo "Installing Service $service"
+		echo '  installing Node'
+		type nvm && nvm install
+		type nvm && nvm use
+		echo '  installing Dependencies'
 		npm install
 		popd
 	done