Move visit_tab! to abstract work package page

spec/support/pages/abstract_work_package.rb

@@ -36,6 +36,10 @@ module Pages
       @work_package = work_package
     end
 
+    def visit_tab!(tab)
+      visit path(tab)
+    end
+
     def expect_subject
       within(container) do
         expect(page).to have_content(work_package.subject)

spec/support/pages/full_work_package.rb

@@ -72,10 +72,6 @@ module Pages
       expect(page).to have_selector(container + ' .user', text: user.name)
     end
 
-    def visit_tab!(tab)
-      visit path(tab)
-    end
-
     def visit_copy!
       page = FullWorkPackageCreate.new(work_package)
       page.visit!