travis: bump ubuntu to 18.04 LTS

lucab · lucab · commit 0c074741ab2c · 2018-05-09T09:36:06.000Z
diff --git a/.travis.yml b/.travis.yml
@@ -10,7 +10,7 @@ env:
     - GOPATH=/opt
     - BUILD_DIR=/opt/src/github.com/coreos/go-systemd
   matrix:
-    - DOCKER_BASE=ubuntu:16.04
+    - DOCKER_BASE=ubuntu:18.04
     - DOCKER_BASE=debian:stretch
 
 before_install:
