before_install:
 - sudo apt-get update -qq
 - sudo apt-get install -qq libfftw3-dev
 - gem install bundler
language: ruby
rvm:
  - "2.1.4"
  - "2.2.0"  
  - "2.3.1"
  - "2.4.1"

before_install:
 - sudo apt-get update -qq
 - sudo apt-get install -qq libfftw3-dev
 - gem install bundler
language: ruby
rvm:
  - "2.2.10"  
  - "2.3.8"
  - "2.4.5"
  - "2.5.3"

Update Travis test Ruby versions
Update Travis test Ruby versions
