fix(instance): undefined changed should return false

lib/instance.js

@@ -410,7 +410,7 @@ module.exports = (function() {
         this._changed[key] = value;
         return this;
       }
-      return this._changed[key];
+      return this._changed[key] || false;
     }
 
     var changed = Object.keys(this.dataValues).filter(function(key) {

test/unit/instance/changed.test.js

@@ -38,7 +38,7 @@ describe(Support.getTestDialectTeaser('Instance'), function() {
       });
 
       user.set('name', 'a');
-      expect(user.changed('name')).not.to.be.ok;
+      expect(user.changed('name')).to.equal(false);
     });
 
     it('should return true for multiple changed values', function () {

test/unit/instance/set.test.js

@@ -9,7 +9,7 @@ var chai = require('chai')
 
 describe(Support.getTestDialectTeaser('Instance'), function() {
   describe('set', function () {
-    it.only('sets nested keys in JSON objects', function () {
+    it('sets nested keys in JSON objects', function () {
       var User = this.sequelize.define('User', {
         meta: DataTypes.JSONB
       });