Add missing argument

Author: webpolis

lib/index.js

@@ -227,8 +227,8 @@ var Embark = {
     var self = this;
     async.waterfall([
       function buildAndDeploy(callback) {
-        Embark.buildAndDeploy(function(contractsManager) {
-          callback(null, contractsManager);
+        Embark.buildAndDeploy(function(err, contractsManager) {
+          callback(err, contractsManager);
         });
       },
       function generateABI(contractsManager, callback) {