Fix buttonbar styles in TWBS3

TWBS3 no longer has form-actions class.

Author: loostro

Resources/public/single-upload/css/single-upload.css

@@ -48,6 +48,10 @@
 
 /* Single upload buttonbar styles */
 .singleupload-buttonbar {
+    margin-top: 20px;
+    margin-bottom: 20px;
+    background-color: #f5f5f5;
+    border-top: 1px solid #e5e5e5;
     padding: 5px 10px;
 }
 
@@ -101,4 +105,4 @@
 
 .single-upload + .help-block {
     margin-top: 20px;
-}
+}