User class email validation (Minor)

[stefanjbloom]

Minor Issue Description

As of right now, a user's email address can literally be anything as long as it is present and unique.

Solution

Simply refactor email attributes validation for format, as well as the current validations. We want to ensure theres an '@' and a '.com'
https://guides.rubyonrails.org/active_record_validations.html#format

Going Forward

While you're addressing this minor issue, think of any other validations that need to be tightened up.