message: Change classes of buttons to match staging osf.io
diff: <div class='btn-toolbar m-t-md'>
  {{#if edit}}
  <div class='btn-group m-l-xs m-t-xs'>
  - <button class='btn btn-sm btn-danger' {{action 'showModal'}}>
  + <button class='btn btn-sm btn-default' {{action 'showModal'}}>
  Delete
  </button>
  </div>
  {{/if}}
  <div class='btn-group m-l-xs m-t-xs'>
  - <button class='btn btn-sm btn-primary popover-toggler'>
  + <button class='btn btn-sm btn-default popover-toggler'>
  Share
  {{#bs-popover placement='bottom' class='share-popover' title='Share'}}
  {{#bs-tab customTabs=true as |tab|}}
  