Merge pull request #1532 from Polymer/0.8-wcjs-0.7.0

Update to wcjs 0.7.0.

Author: kevinpschaaf

bower.json

@@ -17,7 +17,7 @@
     "url": "https://github.com/Polymer/polymer.git"
   },
   "dependencies": {
-    "webcomponentsjs": "^0.6.0"
+    "webcomponentsjs": "^0.7.0"
   },
   "devDependencies": {
     "web-component-tester": "*"