diff --git a/.ruby-version b/.ruby-version
index 94b04ed..4560fb9 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-ruby-2.2.2
+ruby-2.6.3
diff --git a/.travis.yml b/.travis.yml
index 2b78c08..534a90b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,7 +15,8 @@ env:
 install:
   - npm install -g validate-dockerfile
   - gem install bundler
-  - bundle install --without development
+  - bundle config set --local without 'development'
+  - bundle install
 
 script:
   - docklint Dockerfile
diff --git a/Gemfile.lock b/Gemfile.lock
new file mode 100644
index 0000000..ad7eed0
--- /dev/null
+++ b/Gemfile.lock
@@ -0,0 +1,151 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    activesupport (5.2.4.4)
+      concurrent-ruby (~> 1.0, >= 1.0.2)
+      i18n (>= 0.7, < 2)
+      minitest (~> 5.1)
+      tzinfo (~> 1.1)
+    addressable (2.7.0)
+      public_suffix (>= 2.0.2, < 5.0)
+    coderay (1.1.3)
+    concurrent-ruby (1.1.7)
+    diff-lcs (1.4.4)
+    docker-api (2.0.0)
+      excon (>= 0.47.0)
+      multi_json
+    excon (0.78.1)
+    faraday (1.1.0)
+      multipart-post (>= 1.2, < 3)
+      ruby2_keywords
+    faraday_middleware (1.0.0)
+      faraday (~> 1.0)
+    ffi (1.13.1)
+    formatador (0.2.5)
+    gh (0.18.0)
+      activesupport (~> 5.0)
+      addressable (~> 2.4)
+      faraday (~> 1.0)
+      faraday_middleware (~> 1.0)
+      multi_json (~> 1.0)
+      net-http-persistent (~> 2.9)
+      net-http-pipeline
+    git (1.7.0)
+      rchardet (~> 1.8)
+    growl (1.0.3)
+    guard (2.16.2)
+      formatador (>= 0.2.4)
+      listen (>= 2.7, < 4.0)
+      lumberjack (>= 1.0.12, < 2.0)
+      nenv (~> 0.1)
+      notiffany (~> 0.0)
+      pry (>= 0.9.12)
+      shellany (~> 0.0)
+      thor (>= 0.18.1)
+    guard-compat (1.2.1)
+    guard-rspec (4.7.3)
+      guard (~> 2.1)
+      guard-compat (~> 1.1)
+      rspec (>= 2.99.0, < 4.0)
+    highline (2.0.3)
+    i18n (1.8.5)
+      concurrent-ruby (~> 1.0)
+    json (2.3.1)
+    json_pure (2.3.1)
+    launchy (2.4.3)
+      addressable (~> 2.3)
+    listen (3.3.3)
+      rb-fsevent (~> 0.10, >= 0.10.3)
+      rb-inotify (~> 0.9, >= 0.9.10)
+    lumberjack (1.2.8)
+    method_source (1.0.0)
+    minitest (5.14.2)
+    multi_json (1.15.0)
+    multipart-post (2.1.1)
+    nenv (0.3.0)
+    net-http-persistent (2.9.4)
+    net-http-pipeline (1.0.1)
+    net-scp (3.0.0)
+      net-ssh (>= 2.6.5, < 7.0.0)
+    net-ssh (6.1.0)
+    net-telnet (0.1.1)
+    notiffany (0.1.3)
+      nenv (~> 0.1)
+      shellany (~> 0.0)
+    pry (0.13.1)
+      coderay (~> 1.1)
+      method_source (~> 1.0)
+    public_suffix (4.0.6)
+    pusher-client (0.6.2)
+      json
+      websocket (~> 1.0)
+    rake (13.0.1)
+    rb-fsevent (0.10.4)
+    rb-inotify (0.10.1)
+      ffi (~> 1.0)
+    rchardet (1.8.0)
+    rspec (3.10.0)
+      rspec-core (~> 3.10.0)
+      rspec-expectations (~> 3.10.0)
+      rspec-mocks (~> 3.10.0)
+    rspec-core (3.10.0)
+      rspec-support (~> 3.10.0)
+    rspec-expectations (3.10.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.10.0)
+    rspec-its (1.3.0)
+      rspec-core (>= 3.0.0)
+      rspec-expectations (>= 3.0.0)
+    rspec-mocks (3.10.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.10.0)
+    rspec-support (3.10.0)
+    rspec-wait (0.0.9)
+      rspec (>= 3, < 4)
+    ruby2_keywords (0.0.2)
+    serverspec (2.41.5)
+      multi_json
+      rspec (~> 3.0)
+      rspec-its
+      specinfra (~> 2.72)
+    sfl (2.3)
+    shellany (0.0.1)
+    specinfra (2.82.22)
+      net-scp
+      net-ssh (>= 2.7)
+      net-telnet (= 0.1.1)
+      sfl
+    terminal-notifier-guard (1.7.0)
+    thor (1.0.1)
+    thread_safe (0.3.6)
+    travis (1.10.0)
+      faraday (~> 1.0)
+      faraday_middleware (~> 1.0)
+      gh (~> 0.13)
+      highline (~> 2.0)
+      json_pure (~> 2.3)
+      launchy (~> 2.1, < 2.5.0)
+      pusher-client (~> 0.4)
+    tzinfo (1.2.8)
+      thread_safe (~> 0.1)
+    websocket (1.2.8)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  docker-api
+  git
+  growl
+  guard (~> 2.13)
+  guard-rspec
+  rake
+  rb-fsevent
+  rspec-wait
+  serverspec (~> 2.24)
+  specinfra (~> 2.44)
+  terminal-notifier-guard
+  travis
+
+BUNDLED WITH
+   2.1.2