add python compatibility module

Issue-ID: DOC-823

Change-Id: Ie7477333fedd6a7872fb9b91ed802e51414074be
Signed-off-by: thmsdt <thomas.kulik@telekom.de>
diff --git a/docs/requirements-docs.txt b/docs/requirements-docs.txt
index 71df2ab..097282b 100644
--- a/docs/requirements-docs.txt
+++ b/docs/requirements-docs.txt
@@ -5,3 +5,4 @@
 sphinxcontrib-swaggerdoc
 sphinxcontrib-spelling
 sphinxcontrib-plantuml
+six