Replaced references to tcpcloud image with Mirantis ones

Change-Id: Ieb959e9919dc49bc10a02e5814958ed2ba1cf4f4
diff --git a/src/com/mirantis/mk/Docker.groovy b/src/com/mirantis/mk/Docker.groovy
index 7b57e5b..796cc3c 100644
--- a/src/com/mirantis/mk/Docker.groovy
+++ b/src/com/mirantis/mk/Docker.groovy
@@ -35,7 +35,7 @@
 /**
  * Build step to build docker image.
  *
- * @param dockerHubImg     Name of image on dockerhub (ie: tcpcloud/salt-models-testing)
+ * @param dockerHubImg     Name of image on dockerhub (ie: mirantis/salt-models-testing)
  * @param defaultImg       Image to use if dockerHubImg is not found
  * @return img             Docker image
  */