Address `Bundler could not find compatible versions for gem "bundler":`
Address `Bundler could not find compatible versions for gem "bundler":`

https://travis-ci.org/thoughtbot/factory_bot_rails/jobs/567563177#L333-L355

```ruby
Bundler could not find compatible versions for gem "bundler":
  In rails4.2.gemfile:
    appraisal was resolved to 2.2.0, which depends on
      bundler

    rails (~> 4.2.11) was resolved to 4.2.11.1, which depends on
      bundler (>= 1.3.0, < 2.0)

  Current Bundler version:
    bundler (2.0.2)
This Gemfile requires a different version of Bundler.
Perhaps you need to update Bundler by running `gem install bundler`?

Could not find gem 'bundler (>= 1.3.0, < 2.0)', which is required by gem 'rails
(~> 4.2.11)', in any of the sources.

Bundler could not find compatible versions for gem "cucumber":
  In rails4.2.gemfile:
    cucumber (= 1.3.19)

    aruba was resolved to 0.14.11, which depends on
      cucumber (>= 1.3.19)
The command "bundle install --retry 3 --jobs 8" failed and exited with 6 during .
```

because the latest version of Bundler is 2.0.2 since June 13, 2019

https://rubygems.org/gems/bundler/versions/2.0.2

thoughtbot/factory_girl_rails,thoughtbot/factory_girl_rails