Add store tests, fix issue with pending sort to top

js/test/mocha.config.js

@@ -22,11 +22,13 @@ es6Promise.polyfill();
 import 'mock-local-storage';
 
 import chai from 'chai';
+import chaiAsPromised from 'chai-as-promised';
 import chaiEnzyme from 'chai-enzyme';
 import sinonChai from 'sinon-chai';
 import { WebSocket } from 'mock-socket';
 import jsdom from 'jsdom';
 
+chai.use(chaiAsPromised);
 chai.use(chaiEnzyme());
 chai.use(sinonChai);