Bump xos libraries to version 4.0.0

Change-Id: Ic541ddeb6e87e1208875f28ff5e6c72c597f5ec0
diff --git a/requirements.txt b/requirements.txt
index d1f251f..0a02ecd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,3 @@
-xossynchronizer~=3.2.6
-xosapi~=3.2.6
-xoskafka~=3.2.6
+xossynchronizer~=4.0.0
+xosapi~=4.0.0
+xoskafka~=4.0.0