sudo: false
language: ruby
rvm:
  - 2.3.0
  - 2.5.0
before_install: gem install bundler -v 1.6.1

sudo: false
language: ruby
cache: bundler
rvm:
  - 2.3.0
  - 2.5.0
before_install: gem install bundler

Remove hardcoded bundler version and cache bundle
TravisCI: Remove hardcoded bundler version and cache bundle
