Fixing bug in appointment request code that was creating duplicate users
Adding a database constraint to ensure we don't get duplicate users
Adding validation to prevent duplicate email addresses
Break dependency on User in migration
Merge pull request #44 from Devbootcamp/duplicate-user-fix-use-sql-in-migration

Use SQL in migration instead of ActiveRecord
Merge pull request #43 from Devbootcamp/duplicate-user-fix

Fixing bug in appointment request code that was creating duplicate users