Remove Ruby 2.5.1
Remove Ruby 2.5.1

Nothing is using it according to `fab [aws_]production
puppet_class:govuk_rbenv::all rbenv.version_in_use:2.5.1`.

alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet