Changes capybara selector to qa-selector

Otherwise capybara hits ambiguous match.

spec/features/contextual_sidebar_spec.rb

@@ -20,7 +20,7 @@ describe 'Contextual sidebar', :js do
     expect(page).to have_selector('.is-showing-fly-out')
-    find('.qa-link-project').hover
+    find('a[data-qa-selector="project_link"]').hover
     expect(page).not_to have_selector('.is-showing-fly-out')
@@ -30,7 +30,7 @@ describe 'Contextual sidebar', :js do
     expect(page).to have_selector('.is-showing-fly-out')
-    find('.qa-link-project').hover
+    find('a[data-qa-selector="project_link"]').hover
     expect(page).to have_selector('.is-showing-fly-out')
   end