Fix typo.

Author: Chris Joel

paper-button-behavior.html

@@ -9,7 +9,7 @@
 -->
 
 <link rel="import" href="../polymer/polymer.html">
-<link rel="import" href="../iron-state-behaviors/iron-button-state.html">
+<link rel="import" href="../iron-behaviors/iron-button-state.html">
 
 <script>