Fixes storage availability check

- When chrome users disable third-party cookies, iframes from recurly.com on merchant pages
  are forbidden from accessing localStorage. This catches exceptions in that scenario and presents the objectStore as a replacement

lib/util/web-storage.js

@@ -1,10 +1,9 @@
 const debug = require('debug')('recurly:web-storage');
 
 export const NAMESPACE = '__recurly__';
-
 export const STORES = {
-  local: window.localStorage,
-  session: window.sessionStorage
+  local: () => window.localStorage,
+  session: () => window.sessionStorage
 };
 
 export const objectStore = {
@@ -16,7 +15,6 @@ export const objectStore = {
 };
 
 const namespaced = key => `${NAMESPACE}.${key}`;
-const store = scope => available() ? STORES[scope] : objectStore;
 
 /**
  * Fetches a value from web storage, optionally setting its value
@@ -44,14 +42,14 @@ export function set ({ scope = 'local', key, value }) {
   return store(scope).getItem(namespaced(key));
 }
 
-// Test for availability of storage by setting and removing the namespace
-function available () {
+function store (scope) {
   try {
-    STORES.local.setItem(NAMESPACE, NAMESPACE);
-    STORES.local.removeItem(NAMESPACE);
+    const store = STORES[scope]();
+    store.setItem(NAMESPACE, NAMESPACE);
+    store.removeItem(NAMESPACE);
+    return store;
   } catch (e) {
     debug('Web storage is not available due to', e);
-    return false;
+    return objectStore;
   }
-  return true;
-};
+}

webpack.config.js

@@ -1,4 +1,4 @@
-var ExtractTextPlugin = require("extract-text-webpack-plugin");
+var ExtractTextPlugin = require('extract-text-webpack-plugin');
 var path = require('path');
 var minify = ~process.argv.indexOf('-p');