tsk-37: Add last login to service user (#38)

Closes #37

Reviewed-on: phoenix/textsender-models#38
Co-authored-by: phoenix <kundeng00@pm.me>
Co-committed-by: phoenix <kundeng00@pm.me>

tx0/user/service_user.go

@@ -9,7 +9,8 @@ import (
 type ServiceUser struct {
 	Id uuid.UUID `json:"id"`
 	// TODO: Remove the omitempty tags at a later point
-	Username   string    `json:"username,omitempty"`
-	Passphrase string    `json:"passphrase,omitempty"`
-	Created    time.Time `json:"created"`
+	Username   string     `json:"username,omitempty"`
+	Passphrase string     `json:"passphrase,omitempty"`
+	Created    time.Time  `json:"created"`
+	LastLogin  *time.Time `json:"last_login,omitempty"`
 }