fix tests

src/test/acme2-test.js

@@ -5,25 +5,13 @@
 
 'use strict';
 
-var async = require('async'),
-    database = require('../database.js'),
-    acme2 = require('../acme2.js'),
+const acme2 = require('../acme2.js'),
+    common = require('./common.js'),
     expect = require('expect.js');
 
 describe('Acme2', function () {
-    before(function (done) {
-        async.series([
-            database.initialize,
-            database._clear
-        ], done);
-    });
-
-    after(function (done) {
-        async.series([
-            database._clear,
-            database.uninitialize
-        ], done);
-    });
+    before(common.setup);
+    after(common.cleanup);
 
     describe('getChallengeSubdomain', function () {
         it('non-wildcard', function () {