Update Polymer components.

third_party/polymer/components/paper-styles/.bower.json

 {
   "name": "paper-styles",
-  "version": "1.2.1",
+  "version": "1.3.1",
   "description": "Common (global) styles for Material Design elements.",
   "authors": [
     "The Polymer Authors"
   ],
   "keywords": [
     "web-component",
     "polymer",
     "style"
   ],
   "repository": {
     "type": "git",
     "url": "git://github.com/PolymerElements/paper-styles.git"
   },
   "main": "paper-styles.html",
   "license": "http://polymer.github.io/LICENSE.txt",
   "homepage": "https://github.com/polymerelements/paper-styles/",
   "ignore": [
     "/.*"
   ],
   "dependencies": {
     "iron-flex-layout": "PolymerElements/iron-flex-layout#^1.0.0",
     "font-roboto": "PolymerElements/font-roboto#^1.0.1",
     "polymer": "Polymer/polymer#^1.0.0"
   },
   "devDependencies": {
     "webcomponentsjs": "webcomponents/webcomponentsjs#^0.7.0",
     "iron-component-page": "polymerelements/iron-component-page#^1.0.0",
     "web-component-tester": "^4.0.0"
   },
-  "_release": "1.2.1",
+  "_release": "1.3.1",
   "_resolution": {
     "type": "version",
-    "tag": "v1.2.1",
-    "commit": "690f90a4cba3e4f3ab778090e71992f93aafe779"
+    "tag": "v1.3.1",
+    "commit": "1ed324102daa36458d153dd20eac80be9758b00e"
   },
   "_source": "https://github.com/PolymerElements/paper-styles.git",
   "_target": "^1.0.0",
   "_originalSource": "PolymerElements/paper-styles"
 }