listen for error events and proxy them to the transaction

lib/transaction.js

@@ -55,7 +55,7 @@ Transaction.prototype.begin = function(callback) {
     .getQueryInterface()
     .startTransaction(this, {})
     .success(callback)
-
+    .error(onError.bind(this))
 }
 
 Transaction.prototype.setAutocommit = function(callback) {
@@ -64,6 +64,7 @@ Transaction.prototype.setAutocommit = function(callback) {
     .getQueryInterface()
     .setAutocommit(this, this.options.autocommit)
     .success(callback)
+    .error(onError.bind(this))
 }
 
 Transaction.prototype.setIsolationLevel = function(callback) {
@@ -72,5 +73,11 @@ Transaction.prototype.setIsolationLevel = function(callback) {
     .getQueryInterface()
     .setIsolationLevel(this, this.options.isolationLevel)
     .success(callback)
-    .error(function(err) { console.log(err) })
+    .error(onError.bind(this))
+}
+
+// private
+
+var onError = function(err) {
+  this.emit('error', err)
 }