Testing out a travis 7. Trying to cache the docker images.

.travis.yml

@@ -14,13 +14,19 @@ branches:
 
 env:
   - DOCKER_COMPOSE_VERSION=1.25.5
+cache:
+  directories:
+  - docker_images
 
 before_install:
   - sudo rm /usr/local/bin/docker-compose
   - curl -L https://github.com/docker/compose/releases/download/${DOCKER_COMPOSE_VERSION}/docker-compose-`uname -s`-`uname -m` > docker-compose
   - chmod +x docker-compose
   - sudo mv docker-compose /usr/local/bin
+  - docker load -i docker_images/images.tar || true
   - cd docker/travis
+before_cache:
+  - docker save -o docker_images/images.tar $(docker images -a -q)
 # install:
 #   - docker build -t hnakamur/example .
 script: