title: How to upgrade ruby version in Amazon Linux system?
body: <p>I have developed ruby application using padrino ruby framework.
  And I would like to deploy it on Amazon.</p>
  
  <p>I used this image.
  Amazon Linux AMI 2017.09.1 (HVM), SSD Volume Type</p>
  
  <p>And image description was:</p>
  
  <blockquote>
    <p>"The Amazon Linux AMI is an EBS-backed, AWS-supported image. The default image includes AWS command line tools, Python, Ruby, Perl, and Java. The repositories include Docker, PHP, MySQL, PostgreSQL, and other packages."</p>
  </blockquote>
  
  <p>After launching instance, I tested ruby version and it was <code>ruby 2.0.0p648 (2015-12-16) [x86_64-linux]</code> but I need ruby2.4 to deploy padrino framework.
  I tried to update ruby version with no success for whole day.
  console says current version is latest version and there is no ruby2.4
  How to solve this?(I updated gem version to 2.7.2)</p>