Replace all Ubuntu 16.04 with Ubuntu18.04 image
Change-Id: I86b84957145f7c1f253d3158e42e015c322788eb
diff --git a/jjb/onos-app-release.yaml b/jjb/onos-app-release.yaml
index 92cf4f1..e168556 100644
--- a/jjb/onos-app-release.yaml
+++ b/jjb/onos-app-release.yaml
@@ -69,7 +69,7 @@
default: '{jdk-distribution}'
description: 'Distribution of the JDK to use with update-java-alternatives'
- node: 'ubuntu16.04-basebuild-1c-2g'
+ node: 'ubuntu18.04-basebuild-1c-2g'
project-type: pipeline
concurrent: true