Merge ruby-build v20201118

ruby-build 20201118

* tag 'refs/rbtags/v20201118':
  ruby-build 20201118
  Add TruffleRuby GraalVM 20.3.0
  ruby-build 20201117
  Add TruffleRuby 20.3.0
  bump version to openssl-1.1.1g to 1.1.1h
  bump version to openssl-1.1.0j to 1.1.1h
  bump version to openssl-1.1.1d to 1.1.1h
  bump version to 20201005
  Add definition for Ruby 2.7.2
  bump version to 20200926
  Add definition for 3.0.0-preview1
  Rename 2.8.0 to 3.0.0
  ruby-build 20200819
  Add GraalVM 20.2.0
  Add TruffleRuby 20.2.0
  Add definition for mruby 2.1.2
  Add definition for JRuby 9.2.13.0
  Rename CONDUCT.md to CODE_OF_CONDUCT.md
  ruby-build 20200727
  Fix installation of truffleruby+graalvm on macOS

Author: jasonkarns