Replace all Ubuntu 16.04 with Ubuntu18.04 image
Change-Id: I86b84957145f7c1f253d3158e42e015c322788eb
diff --git a/jjb/defaults.yaml b/jjb/defaults.yaml
index 34cb3e1..b26ea25 100644
--- a/jjb/defaults.yaml
+++ b/jjb/defaults.yaml
@@ -56,7 +56,7 @@
# The most frequently used type of Build Executor. Name is per the LF global-jjb.
# See build node types under "Cloud > Amazon EC2" at
# https://jenkins.opencord.org/configure
- build-node: ubuntu16.04-basebuild-1c-1g
+ build-node: ubuntu18.04-basebuild-1c-1g
# CORD Gerrit server definition, set in configuration
gerrit-server-name: 'CORD Gerrit'