Bump xos libraries to version 4.0.0

Change-Id: Ic541ddeb6e87e1208875f28ff5e6c72c597f5ec0
diff --git a/xos/synchronizer/config.yaml b/xos/synchronizer/config.yaml
index f6f1690..5085f72 100644
--- a/xos/synchronizer/config.yaml
+++ b/xos/synchronizer/config.yaml
@@ -15,7 +15,7 @@
 
 
 name: att-workflow-driver
-core_version: ">=2.2.1"
+core_version: ">=4.0.0"
 required_models:
   - AttWorkflowDriverService
   - AttWorkflowDriverServiceInstance