fix(opera): Polyfill String.endsWith

Opera doesn't support this method

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/endsWith#Browser_compatibility

Closes #213

Author: saiichihashimoto

extension/index.background.js

@@ -1,4 +1,5 @@
 require('../report');
+require('string.prototype.endswith');
 var createStore = require('../redux/createStore.background');
 
 require('./browser-action');

extension/index.options.js

@@ -1,4 +1,5 @@
 require('../report');
+require('string.prototype.endswith');
 var Provider = require('react-redux').Provider;
 var React    = require('react');
 var ReactDOM = require('react-dom');

extension/index.top-frame.js

@@ -1,4 +1,5 @@
 require('../report');
+require('string.prototype.endswith');
 var Provider = require('react-redux').Provider;
 var React    = require('react');
 var ReactDOM = require('react-dom');

package.json

@@ -87,6 +87,7 @@
     "request": "^2.74.0",
     "reselect": "^2.5.3",
     "snoocore": "^3.2.0",
+    "string.prototype.endswith": "^0.2.0",
     "twit": "^2.1.1",
     "underscore": "^1.8.3",
     "universal-analytics": "^0.4.2",