Fix missing space

Author: gwak

test-app/app/templates/index.hbs

@@ -129,7 +129,7 @@
             groupName='grid'
           }}>
             {{#each @model.itemsGrid as |item|~}}
-              <div class="col-120" data-test-grid-demo-handle tabindex='0'{{sortable-item model=item groupName='grid'}}>
+              <div class="col-120" data-test-grid-demo-handle tabindex='0' {{sortable-item model=item groupName='grid'}}>
                 <div class="card">
                   <ItemPresenter @item={{item}} />
                 </div>