Fix #494: Reject a promise on error condition

Author: nrchandan

src/ParseObject.js

@@ -1847,6 +1847,8 @@ var DefaultController = {
             }, options);
           }).then((response, status, xhr) => {
             batchReturned.resolve(response, status);
+          }, (error) => {
+            batchReturned.reject(new ParseError(error.message));
           });
 
           return ParsePromise.when(batchTasks);