Helper cleanup (#1348)

* Remove unused helper files

* Add coverage for application helper

* Add coverage for StreamEntriesHelper #display_name

spec/helpers/application_helper_spec.rb

@@ -1,5 +1,19 @@
 require 'rails_helper'
 
-RSpec.describe ApplicationHelper, type: :helper do
+describe ApplicationHelper do
+  describe 'active_nav_class' do
+    it 'returns active when on the current page' do
+      allow(helper).to receive(:current_page?).and_return(true)
 
+      result = helper.active_nav_class("/test")
+      expect(result).to eq "active"
+    end
+
+    it 'returns empty string when not on current page' do
+      allow(helper).to receive(:current_page?).and_return(false)
+
+      result = helper.active_nav_class("/test")
+      expect(result).to eq ""
+    end
+  end
 end