Capitalize tab titles

app/helpers/blob_helper.rb

@@ -60,7 +60,7 @@ module BlobHelper
     if Gitlab::MarkupHelper.previewable?(filename)
       'Preview'
     else
-      'Preview changes'
+      'Preview Changes'
     end
   end
 

app/views/projects/blob/edit.html.haml

@@ -5,12 +5,12 @@
   %ul.center-top-menu.no-bottom.js-edit-mode
     %li.active
       = link_to '#editor' do
-        %i.fa.fa-edit
-        Edit file
+        = icon('edit')
+        Edit File
 
     %li
       = link_to '#preview', 'data-preview-url' => namespace_project_preview_blob_path(@project.namespace, @project, @id) do
-        %i.fa.fa-eye
+        = icon('eye')
         = editing_preview_title(@blob.name)
 
   = form_tag(namespace_project_update_blob_path(@project.namespace, @project, @id), method: :put, class: 'form-horizontal js-requires-input js-edit-blob-form') do

features/steps/project/source/browse_files.rb

@@ -87,7 +87,7 @@ class Spinach::Features::ProjectSourceBrowseFiles < Spinach::FeatureSteps
   end
 
   step 'I click link "Diff"' do
-    click_link 'Preview changes'
+    click_link 'Preview Changes'
   end
 
   step 'I click on "Commit Changes"' do