Fix condition in model wide validation

docs/docs/models.md

@@ -327,7 +327,7 @@ var Pub = Sequelize.define('Pub', {
 }, {
   validate: {
     bothCoordsOrNone: function() {
-      if ((this.latitude === null) === (this.longitude === null)) {
+      if ((this.latitude === null) !== (this.longitude === null)) {
         throw new Error('Require either both latitude and longitude or neither')
       }
     }