Convert the adapter error to an actual js error in authenticate

lib/sequelize.js

@@ -593,7 +593,9 @@ module.exports = (function() {
    * @return {Promise}
    */
   Sequelize.prototype.authenticate = function() {
-    return this.query('SELECT 1+1 AS result', null, { raw: true, plain: true }).return()
+    return this.query('SELECT 1+1 AS result', null, { raw: true, plain: true }).return().catch(function (err) {
+      throw new Error(err)
+    })
   }
 
   Sequelize.prototype.validate = Sequelize.prototype.authenticate;