refactor(aria/tree): removes unnecessary space

Updates stylesheet to remove unnecessary spacing.

Author: essjay05

src/components-examples/aria/tree/tree-common.css

@@ -52,7 +52,6 @@
   transform: scaleX(-1) rotate(90deg);
 }
 
-
 .example-selected-icon {
   visibility: hidden;
   margin-left: auto;