Remove duplication from test

This is being done by:
- Creating a new context for tests that have the same pre-condition
- Creating a before block for the pre-condition so it doesn't need
to be duplicated in all the three affected tests.

qa/qa/specs/features/ee/browser_ui/2_plan/epic/epics_management_spec.rb

@@ -37,9 +37,12 @@ module QA
         let(:issue) { create_issue_resource }
         let(:epic)  { create_epic_resource(issue.project.group) }
 
-        it 'adds/removes issue to/from epic' do
+        context 'Visit epic first' do
+          before do
             epic.visit!
+          end
 
+          it 'adds/removes issue to/from epic' do
             EE::Page::Group::Epic::Show.perform do |show|
               show.add_issue_to_epic(issue.web_url)
 
@@ -52,8 +55,6 @@ module QA
           end
 
           it 'comments on epic' do
-          epic.visit!
-
             comment = 'My Epic Comment'
             EE::Page::Group::Epic::Show.perform do |show|
               show.add_comment_to_epic(comment)
@@ -63,8 +64,6 @@ module QA
           end
 
           it 'closes and reopens an epic' do
-          epic.visit!
-
             EE::Page::Group::Epic::Show.perform(&:close_reopen_epic)
 
             expect(page).to have_content('Closed')
@@ -73,6 +72,7 @@ module QA
 
             expect(page).to have_content('Open')
           end
+        end
 
         it 'adds/removes issue to/from epic using quick actions' do
           issue.visit!