[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-synchronizer/.gitignore b/lib/xos-synchronizer/.gitignore
index 5be50bc..b0b91ee 100644
--- a/lib/xos-synchronizer/.gitignore
+++ b/lib/xos-synchronizer/.gitignore
@@ -4,4 +4,7 @@
 dist
 .coverage
 coverage.xml
-cover
\ No newline at end of file
+cover
+
+# setup.py copies this, don't commit it
+VERSION