Add tests for accounts, and fix allowing user to delete friend code with active trade offers and in-game-name not being set on signup

accounts/forms.py

@@ -74,12 +74,13 @@ class CustomUserCreationForm(SignupForm):
     def save(self, request):
         # First, complete the normal signup process.
         user = super(CustomUserCreationForm, self).save(request)
-        # Create the associated FriendCode record.
-        friend_code_pk = FriendCode.objects.create(
+        # Create the associated FriendCode record, now including in_game_name.
+        friend_code_instance = FriendCode.objects.create(
             friend_code=self.cleaned_data["friend_code"],
+            in_game_name=self.cleaned_data["in_game_name"],
             user=user
         )
-        user.default_friend_code = friend_code_pk
+        user.default_friend_code = friend_code_instance
         user.save()
         return user