ErrEmailInvalid is returned when an email address provided does not match any of our formatting requirements.

ErrEmailRequired is returned when no email address is provided when a user is created.

ErrEmailTaken is returned when an update or create is attempted with an email address that is already in use.

ErrIDInvalid is returned when an invalid ID is provided to a method like Delete().

ErrNotFound is returned when a resource is not found in the database.

ErrPasswordRequired is returned when a create is attempted without a password.

ErrPasswordTooShort is returned when an update or create is attempted with a password <8 characters.

ErrRememberRequired is returned when a create or update is attempted without without a user remember token hash.

ErrRememberTooShort is returned when a remember token is not atlease 32 bytes in length.

User represents the user model in the database.

UserDB is used to interact with the users database.

UserService is a set of methods used to manipulate and work with the user model.