Using up caret icon for dropdown.

src/filebrowser/buttons.ts

@@ -289,7 +289,7 @@ namespace Private {
     createIcon.className = ICON_CLASS + ' fa fa-plus';
     uploadIcon.className = ICON_CLASS + ' fa fa-upload';
     refreshIcon.className = ICON_CLASS + ' fa fa-refresh';
-    dropdownIcon.className = DROPDOWN_CLASS + ' fa fa-caret-down';
+    dropdownIcon.className = DROPDOWN_CLASS + ' fa fa-caret-up';
 
     createContent.appendChild(createIcon);
     createContent.appendChild(dropdownIcon);