Better commit button after file edit

app/views/edit_tree/show.html.haml

@@ -23,7 +23,7 @@
       = hidden_field_tag 'last_commit', @last_commit
       = hidden_field_tag 'content', '', id: :file_content
       .commit-button-annotation
-        = button_tag "Commit", class: 'btn commit-btn js-commit-button'
+        = button_tag "Commit changes", class: 'btn commit-btn js-commit-button btn-primary'
         .message
           to branch
           %strong= @ref