Fix factories

spec/factories/groups.rb

@@ -1,7 +1,6 @@
 FactoryBot.define do
   factory :group do
-    name { "MyString" }
-    icon { "MyString" }
+    sequence(:name) { |i| "Group #{i}" }
     order { 1 }
   end
 end

spec/factories/guest.rb

@@ -1,5 +1,7 @@
 FactoryBot.define do
   factory :guest do
+    association :group
+
     first_name { Faker::Name.first_name }
     last_name { Faker::Name.last_name }
     email { Faker::Internet.email }