Add forgot password resolver

Resolves #10

server/enum/verification.go

@@ -5,11 +5,13 @@ type VerificationType int
 const (
 	BasicAuthSignup VerificationType = iota
 	UpdateEmail
+	ForgotPassword
 )
 
 func (d VerificationType) String() string {
 	return [...]string{
 		"basic_auth_signup",
 		"update_email",
+		"forgot_password",
 	}[d]
 }