Use factories to create project/group membership on specs

spec/features/groups/members/sorting_spec.rb

@@ -6,8 +6,8 @@ feature 'Groups > Members > Sorting', feature: true do
   let(:group)     { create(:group) }
 
   background do
-    group.add_owner(owner)
-    group.add_developer(developer)
+    create(:group_member, :owner, user: owner, group: group, created_at: 5.days.ago)
+    create(:group_member, :developer, user: developer, group: group, created_at: 3.days.ago)
 
     login_as(owner)
   end

spec/features/projects/members/sorting_spec.rb

@@ -6,8 +6,8 @@ feature 'Projects > Members > Sorting', feature: true do
   let(:project)   { create(:empty_project) }
 
   background do
-    project.team << [master, :master]
-    project.team << [developer, :developer]
+    create(:project_member, :master, user: master, project: project, created_at: 5.days.ago)
+    create(:project_member, :developer, user: developer, project: project, created_at: 3.days.ago)
 
     login_as(master)
   end