Merge pull request #3140 from linux-on-ibm-z/travis-s390x

Add s390x support for travis

.travis.yml

@@ -1,9 +1,14 @@
-dist: trusty
+dist: bionic
 sudo: required
 # setup travis so that we can run containers for integration tests
 services:
   - docker
 
+jobs:
+  include:
+   - arch: amd64
+   - arch: s390x
+
 language: go
 
 go:
@@ -34,7 +39,7 @@ script:
   - export GOOS=$TRAVIS_GOOS
   - export CGO_ENABLED=$TRAVIS_CGO_ENABLED
   - DCO_VERBOSITY=-q script/validate/dco
-  - GOOS=linux GO111MODULE=off script/setup/install-dev-tools
+  - GOOS=linux GO111MODULE=on script/setup/install-dev-tools
   - script/validate/vendor
   - go build -i .
   - make check