Make user email unique
Make user email unique

TIY-LR-FEE-2015-Fall/library-api,rtablada/x-men-example,rtablada/cars-api,TIY-LR-FEE-2015-Fall/library-api,rtablada/cars-api,rtablada/x-men-example,rtablada/express-shell,TIY-LR-FEE-2015-Fall/library-api,rtablada/express-shell,rtablada/express-shell,rtablada/api-kit,rtablada/api-kit,rtablada/api-kit,rtablada/x-men-example,rtablada/cars-api