Fixed wrong use of moment

no issue

- whilst updating moment, a test that was doing timezone calculation was
  failing. We were only importing moment before, and not moment-timezone
- this commit fixes that

test/regression/importer/importer_spec.js

@@ -2,7 +2,7 @@ const should = require('should');
 const sinon = require('sinon');
 const testUtils = require('../../utils');
 const Promise = require('bluebird');
-const moment = require('moment');
+const moment = require('moment-timezone');
 const ObjectId = require('bson-objectid');
 const assert = require('assert');
 const _ = require('lodash');