migrate to "export default"

also, set no-use-before-define in linter

src/test/groups-test.js

@@ -1,9 +1,9 @@
 /* jslint node:true */
 
 import BoxError from '../boxerror.js';
-import * as common from './common.js';
+import common from './common.js';
 import expect from 'expect.js';
-import * as groups from '../groups.js';
+import groups from '../groups.js';
 import safe from 'safetydance';
 
 /* global it:false */