add python compatibility module

Issue-ID: DOC-823

Change-Id: I9029058ec72fbc90288787d253ea9f6df2086081
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