Bump required version of Polymer

Related to #223

Author: rictic

bower.json

@@ -28,7 +28,7 @@
   "homepage": "https://github.com/PolymerElements/paper-input",
   "ignore": [],
   "dependencies": {
-    "polymer": "Polymer/polymer#^1.1.0",
+    "polymer": "Polymer/polymer#^1.2.0",
     "iron-autogrow-textarea": "PolymerElements/iron-autogrow-textarea#^1.0.0",
     "iron-behaviors": "PolymerElements/iron-behaviors#^1.0.0",
     "iron-form-element-behavior": "PolymerElements/iron-form-element-behavior#^1.0.0",