Update Polymer from 1.2.1 -> 1.2.3

third_party/polymer/v1_0/components-chromium/iron-pages/bower.json

 {
   "name": "iron-pages",
-  "version": "1.0.3",
+  "version": "1.0.4",
   "license": "http://polymer.github.io/LICENSE.txt",
   "description": "Organizes a set of pages and shows one at a time",
   "main": "iron-pages.html",
   "private": true,
   "authors": [
     "The Polymer Authors"
   ],
   "repository": {
     "type": "git",
     "url": "git://github.com/PolymerElements/iron-pages.git"
   },
   "keywords": [
     "web-components",
     "polymer",
     "container"
   ],
   "dependencies": {
     "iron-resizable-behavior": "polymerelements/iron-resizable-behavior#^1.0.0",
     "iron-selector": "polymerelements/iron-selector#^1.0.0",
     "polymer": "Polymer/polymer#^1.0.0"
   },
   "devDependencies": {
     "paper-styles": "polymerelements/paper-styles#^1.0.2",
     "iron-component-page": "polymerelements/iron-component-page#^1.0.0",
     "test-fixture": "polymerelements/test-fixture#^1.0.0",
-    "web-component-tester": "*",
+    "web-component-tester": "polymer/web-component-tester#^3.4.0",
     "webcomponentsjs": "webcomponents/webcomponentsjs#^0.7.0"
-  }
+  },
+  "ignore": []
 }