Swap addHusband and addWife action

Just to make sure couple addition does not interfere
the order of person marriage

tests/Unit/UserTest.php

@@ -52,8 +52,8 @@ class UserTest extends TestCase
         $husband = factory(User::class)->states('male')->create();
         $wife1 = factory(User::class)->states('female')->create();
         $wife2 = factory(User::class)->states('female')->create();
-        $husband->addWife($wife1, '1990-02-13');
         $husband->addWife($wife2, '1999-04-21');
+        $husband->addWife($wife1, '1990-02-13');
 
         $husband = $husband->fresh();
         $marriages = $husband->marriages;
@@ -73,8 +73,8 @@ class UserTest extends TestCase
         $wife = factory(User::class)->states('female')->create();
         $husband1 = factory(User::class)->states('male')->create();
         $husband2 = factory(User::class)->states('male')->create();
-        $wife->addHusband($husband1, '1980-02-13');
         $wife->addHusband($husband2, '1989-04-21');
+        $wife->addHusband($husband1, '1980-02-13');
 
         $wife = $wife->fresh();
         $marriages = $wife->marriages;