Project download buttons always show

This was hidden when the viewport was was below the 'hidden-sm' theshold. Now it displays the same as the rest of the 'project-repo-buttons' block.

app/views/projects/buttons/_download.html.haml

 - if !project.empty_repo? && can?(current_user, :download_code, project)
-  %span{class: 'hidden-xs hidden-sm download-button'}
+  %span{class: 'download-button'}
     .dropdown.inline
       %button.btn{ 'data-toggle' => 'dropdown' }
         = icon('download')

changelogs/unreleased/always-show-download-button.yml

+---
+title: Project download buttons always show
+merge_request: 7405
+author: Philip Karpiak