add NAMED_IAM capability to cfn stack creation

Change-Id: I5951d7b2ed702efa94f29f41fef8e757556ad901
diff --git a/src/com/mirantis/mk/Aws.groovy b/src/com/mirantis/mk/Aws.groovy
index 8c15e2d..fc64c25 100644
--- a/src/com/mirantis/mk/Aws.groovy
+++ b/src/com/mirantis/mk/Aws.groovy
@@ -38,7 +38,7 @@
 def createStack(venv_path, env_vars, template_file, stack_name, parameters = []) {
     def python = new com.mirantis.mk.Python()
 
-    def cmd = "aws cloudformation create-stack --stack-name ${stack_name} --template-body file://template/${template_file} --capabilities CAPABILITY_IAM"
+    def cmd = "aws cloudformation create-stack --stack-name ${stack_name} --template-body file://template/${template_file} --capabilities CAPABILITY_NAMED_IAM"
 
     if (parameters != null && parameters.size() > 0) {
         cmd = "${cmd} --parameters"