.travis.yml in fourtrack-0.2.1 vs .travis.yml in fourtrack-0.3.1

@@ -1,5 +1,7 @@
+dist: trusty # https://docs.travis-ci.com/user/trusty-ci-environment/
 sudo: false
-language: ruby
+cache: bundler
+
 rvm:
   - 2.2.5
-before_install: gem install bundler -v 1.12.5
+  - 2.3.3