Bump xos libraries to version 4.0.0

Change-Id: Ibd20e72a594fa88df77904acc70e1f852ea2e15e
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