tests: add favorite groups controller tests.

test/factories/favorite_group.rb

@@ -1,4 +1,6 @@
 FactoryGirl.define do
-  factory(:favorite_group) do
+  factory :favorite_group do
+    name { FFaker::Lorem.word }
+    creator
   end
 end

test/factories/user.rb

@@ -1,5 +1,5 @@
 FactoryGirl.define do
-  factory(:user) do
+  factory(:user, aliases: [:creator, :updater]) do
     name {(rand(1_000_000) + 10).to_s}
     password "password"
     password_hash {User.sha1("password")}