sh 'rvm use ruby 2.3.1'

+ rvm use ruby 2.3.1
 RVM is not a function, selecting rubies with 'rvm use ...' will not work.

sh '''
    #!/bin/bash -xl
    echo $PATH
    rvm install ruby-2.3.1
    rvm alias create default 2.3.1 && ruby --version
    ruby --version
  '''