.travis.yml in r10k-3.2.3 vs .travis.yml in r10k-3.3.0

@@ -1,14 +1,16 @@
 ---
 language: ruby
+services:
+  - docker
 bundler_args: "--without system"
 script: "bundle exec rspec --color --format documentation spec/unit"
 notifications:
   email: false
 sudo: false
 jdk:
-  - openjdk8
+    - oraclejdk8
 before_install: gem install bundler -v '< 2' --no-document
 matrix:
   include:
     - stage: r10k tests
       rvm: 2.5.0
@@ -16,5 +18,22 @@
       rvm: 2.4.0
     - stage: r10k tests
       rvm: 2.3.0
     - stage: r10k tests
       rvm: jruby
+    - stage: r10k container tests
+      language: ruby
+      rvm: 2.5.5
+      env:
+        - DOCKER_COMPOSE_VERSION=1.24.0
+      script:
+        - |
+          set -ex
+          sudo rm /usr/local/bin/docker-compose
+          curl --location https://github.com/docker/compose/releases/download/${DOCKER_COMPOSE_VERSION}/docker-compose-`uname --kernel-name`-`uname --machine` > docker-compose 
+          chmod +x docker-compose
+          sudo mv docker-compose /usr/local/bin
+          cd docker
+          make lint
+          make build
+          make test
+          set +x