improve async test

Author: jfromaniello

test/async_sign.tests.js

@@ -1,16 +1,15 @@
 var jwt = require('../index');
-
 var expect = require('chai').expect;
 
 describe('signing a token asynchronously', function() {
 
   describe('when signing a token', function() {
     var secret = 'shhhhhh';
-    var syncToken = jwt.sign({ foo: 'bar' }, secret, { algorithm: 'HS256' });
 
     it('should return the same result as singing synchronously', function(done) {
       jwt.sign({ foo: 'bar' }, secret, { algorithm: 'HS256' }, function (err, asyncToken) {
         if (err) return done(err);
+        var syncToken = jwt.sign({ foo: 'bar' }, secret, { algorithm: 'HS256' });
         expect(asyncToken).to.be.a('string');
         expect(asyncToken.split('.')).to.have.length(3);
         expect(asyncToken).to.equal(syncToken);