fix ci config

Author: wuhuizuo

.travis.yml

@@ -1,4 +1,5 @@
-sudo: false
+sudo: required
+services: docker
 language: ruby
 rvm:
   - 2.0.0
@@ -8,9 +9,16 @@ rvm:
   - 2.3.4
   - 2.4.0
   - 2.4.1
+  - 2.5.0
 before_install: gem install bundler
 install: bundle
 script:
   - bundle exec rspec
-deploy:
-  -
+after_success:
+  - docker build -t $REPO:$(cat Dockerfile.version) .
+  - docker tag $REPO:$(cat Dockerfile.version) $REPO:latest
+  - if [ "$TRAVIS_BRANCH" == "master" ]; then
+      docker login -u="$REGISTRY_USERNAME" -p="$REGISTRY_PASSWORD" $REGISTRY;
+      docker push $REPO:$(cat Dockerfile.version);
+      docker push $REPO:latest;
+    fi