title: Heroku thinks I'm trying to install Ruby 2.5.1 in my app, won't deploy
body: <p>I'm new to Heroku and am not a developer, but am following directions on how to create an app based on a template. The instructions are here btw:
  <a href="https://github.com/syncforynab/fintech-to-ynab/wiki/Getting-Started" rel="nofollow noreferrer">https://github.com/syncforynab/fintech-to-ynab/wiki/Getting-Started</a></p>
  <p>And here's the template:
  <a href="https://heroku.com/deploy?template=https://github.com/scottrobertson/fintech-to-ynab" rel="nofollow noreferrer">https://heroku.com/deploy?template=https://github.com/scottrobertson/fintech-to-ynab</a></p>
  <p>Anyway, everything seems to be fine until I hit Deploy. I'm getting the below message that the script is trying to install Rub 2.5.1 and that's too old. I contacted the developer at Github and he said it must be a Heroku glitch as they specify a higher version. Anyone know what's going on here?</p>
  <pre><code>-----&gt; Building on the Heroku-20 stack
  -----&gt; Determining which buildpack to use for this app
  -----&gt; Ruby app detected
  -----&gt; Installing bundler 1.17.3
  -----&gt; Removing BUNDLED WITH version in the Gemfile.lock
  -----&gt; Compiling Ruby/Rails
         Command: 'set -o pipefail; curl -L --fail --retry 5 --retry-delay 1 --connect-timeout 3 --max-time 30 https://s3-external-1.amazonaws.com/heroku-buildpack-ruby/heroku-20/ruby-2.5.1.tgz -s -o - | tar zxf - ' failed on attempt 1 of 3.
         Command: 'set -o pipefail; curl -L --fail --retry 5 --retry-delay 1 --connect-timeout 3 --max-time 30 https://s3-external-1.amazonaws.com/heroku-buildpack-ruby/heroku-20/ruby-2.5.1.tgz -s -o - | tar zxf - ' failed on attempt 2 of 3.
   !
   !     The Ruby version you are trying to install does not exist on this stack.
   !     
   !     You are trying to install ruby-2.5.1 on heroku-20.
   !     
   !     Ruby ruby-2.5.1 is present on the following stacks:
   !     
   !     - cedar-14
   !     - heroku-16
   !     - heroku-18
   !     
   !     Heroku recommends you use the latest supported Ruby version listed here:
   !     https://devcenter.heroku.com/articles/ruby-support#supported-runtimes
   !     
   !     For more information on syntax for declaring a Ruby version see:
   !     https://devcenter.heroku.com/articles/ruby-versions
   !
   !     Push rejected, failed to compile Ruby app.
   !     Push failed
  </code></pre>