Add python-gnupg to hardcoded requirement of model generator

Change-Id: I91645c495c01e3c83086aaa58e172d43d773a440
Related-PROD: PROD-23609 (PROD:23609)
diff --git a/src/com/mirantis/mk/Python.groovy b/src/com/mirantis/mk/Python.groovy
index f135cc0..6183f51 100644
--- a/src/com/mirantis/mk/Python.groovy
+++ b/src/com/mirantis/mk/Python.groovy
@@ -247,7 +247,8 @@
     requirements = [
         'cookiecutter',
         'jinja2==2.8.1',
-        'PyYAML==3.12'
+        'PyYAML==3.12',
+        'python-gnupg==0.4.3'
     ]
     setupVirtualenv(path, 'python2', requirements)
 }