Update test for changed error text

Author: shepmaster

tests/spec/features/highlighting_error_output_spec.rb

@@ -10,7 +10,7 @@
 
   scenario "errors are highlighted" do
     within('.output-stderr') do
-      expect(page).to have_css '.error', text: 'wrong number of type arguments'
+      expect(page).to have_css '.error', text: '1 type argument but 2 type arguments were supplied'
       expect(page).to have_css '.error', text: 'aborting due to 2 previous errors'
       expect(page).to have_css '.error', text: /Could not compile `playground`/i
     end