improving cleanup between tests in order to combat the frequent test failures seen recently

js/test/UiHelper.js

@@ -6,7 +6,7 @@ describe('UiHelper', function () {
     // for now we use a mock function to trigger the event
     describe('historyChange', function () {
         this.timeout(30000);
-        before(function () {
+        beforeEach(function () {
             $.PrivateBin.Helper.reset();
             cleanup();
         });