QA: Remove redundant test so beta cluster tests pass

Currently beta cluster tests are failing because of a single test.

The test for whether a "tagline" appears on special pages is outdated. We now
show taglines on all special pages (defaulting to empty)

Let's thus remove it.

Additional changes:
* Rephrase "wikidata description" as "tagline" - we use the tagline to display
things other than wikidata descriptions e.g. the tagline on Special:MobileOptions

Change-Id: Icb66563cb3a5e7043ca41f59c826bd4247d89d52

tests/browser/features/step_definitions/wikidata_descriptions.rb

@@ -1,7 +1,7 @@
-Then(/^I should see a wikidata description$/) do
+Then(/^I should see a tagline$/) do
   expect(on(ArticlePage).wikidata_description_element).to be_visible
 end
 
-Then(/^I should not see a wikidata description$/) do
+Then(/^I should not see a tagline$/) do
   expect(on(ArticlePage).wikidata_description_element).not_to be_visible
 end

tests/browser/features/wikidata_descriptions.feature

@@ -6,16 +6,12 @@ Feature: Wikidata descriptions
       And I am on the "Main Page" page
 
   Scenario: Description does not appear on Main Page
-    Then I should not see a wikidata description
+    Then I should not see a tagline
 
   Scenario: Description appears on main namespace
     When I am on the "Albert Einstein" page
-    Then I should see a wikidata description
+    Then I should see a tagline
 
   Scenario: Description does not appear on non-main namespaces
     Given I am on the "Talk:Contributions" page
-    Then I should not see a wikidata description
-
-  Scenario: Description does not appear on special pages
-    Given I am on the "Special:Contributions" page
-    Then I should not see a wikidata description
+    Then I should not see a tagline