Bump xos libraries to version 4.0.0

Change-Id: Ic9cde0c71aa018f40882953b849d0ae0a7342754
diff --git a/requirements.txt b/requirements.txt
index 669c29b..0a02ecd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,3 @@
-xossynchronizer~=3.2.1
-xosapi~=3.2.1
-xoskafka~=3.2.1
+xossynchronizer~=4.0.0
+xosapi~=4.0.0
+xoskafka~=4.0.0