added alert if attempt to sign in with username that doesn't exist
Merge pull request #112 from lpappone/master

added alert if attempt to sign in with username that doesn't exist
Modified iOS endpoints to handle failed login/signup as well as a specific user's recommendations from the database.
Modified server to handle greater detail for iOS endpoints
Merge branch 'master' of https://github.com/SunJieMing/beer-finderWeb

Conflicts:
	server/routes.js