[SEBA-450] (part 2)

Add tox testing support on additional XOS library modules:

- xos-api
- xos-kafka (has no tests)
- xos-migrate (has no tests)
- xos-synchronizer

Change-Id: I98195bc9747971d3515882d517affe058dd86ac5
diff --git a/lib/xos-kafka/MANIFEST.in b/lib/xos-kafka/MANIFEST.in
index 9561fb1..b9708d6 100644
--- a/lib/xos-kafka/MANIFEST.in
+++ b/lib/xos-kafka/MANIFEST.in
@@ -1 +1,3 @@
 include README.rst
+include requirements.txt
+include xoskafka/VERSION