begin implementing new preenUserHistory method: port current code to es6 and setup tests

test/common/preenUserHistory.test.js

@@ -0,0 +1,11 @@
+import preenUserHistory from '../../common/script/preenUserHistory'; // eslint-disable-line no-unused-vars
+
+describe('preenUserHistory', () => {
+  describe('preen tasks history', () => {
+    it('works');
+  });
+
+  describe('preen user history', () => {
+    it('works');
+  });
+});