SEBA-298 Upgrade xos-tosca version

Change-Id: I39e62dae5d00ce6156f6a56a12ac35fd8caa7318
diff --git a/xos-core/values.yaml b/xos-core/values.yaml
index 373a228..dfd2c5c 100644
--- a/xos-core/values.yaml
+++ b/xos-core/values.yaml
@@ -28,7 +28,7 @@
 
   xos_tosca:
     repository: 'xosproject/xos-tosca'
-    tag: '1.1.7'
+    tag: '1.1.8'
     pullPolicy: 'Always'
 
   xos_api_tester: