Reload forked_project_link projects

This fixes ./spec/services/projects/unlink_fork_service_spec.rb which
somehow started failing on the master branch. It certainly isn't a very
elegant solution but seems to be the easiest/best way of solving this
problem for the time being.

spec/factories/forked_project_links.rb

@@ -13,5 +13,10 @@ FactoryGirl.define do
   factory :forked_project_link do
     association :forked_to_project, factory: :project
     association :forked_from_project, factory: :project
+
+    after(:create) do |link|
+      link.forked_from_project.reload
+      link.forked_to_project.reload
+    end
   end
 end