Update to wily/ubuntu 15

Change-Id: Ic0dc6a3d9dcdf1453d5837fbf9483acc752f556f
diff --git a/jobs.yaml b/jobs.yaml
index 474755c..479e50c 100644
--- a/jobs.yaml
+++ b/jobs.yaml
@@ -31,8 +31,8 @@
       - precise64server
       - trusty32server
       - trusty64server
-      - utopic32server
-      - utopic64server
+      - wily32server
+      - wily64server
     branch: 'master'
     tag: ''
     jobs: