Allow to use external nodegenerator

  * Switch to downstream reclass
  * Add reference replacement in generator:
   COLON_SYMBOL_FOR_FUTURE_REFERENCE => ':'

https://mirantis.jira.com/browse/PROD-30702

Change-Id: I342e2e3abc770f3a150668df06cc06fe0f3e2687
diff --git a/tests/pillar/storage_git.sls b/tests/pillar/storage_git.sls
index 7dd9aba..c8dd687 100644
--- a/tests/pillar/storage_git.sls
+++ b/tests/pillar/storage_git.sls
@@ -4,5 +4,5 @@
     base_dir: /srv/reclass
     source:
       engine: git
-      repo: git+https://github.com/salt-formulas/reclass
-      branch: master
+      repo: git+http://gerrit.mcp.mirantis.com/packaging/sources/reclass
+      branch: mcp/xenial/extra