Fix "Insecure world writable dir" warnings

Fixes #16.

Follow ruby-install-builder => ruby-builder repository rename

v1.12.1

Rename generate script

Add support for ruby-head

See #15.

Add support for truffleruby-head

v1.11.0

Add support for truffleruby-head

Use the SSD drive on Windows

See #14

Store the available versions in this repository

• Add support for Rubinius on ubuntu-latest (#5).

Add support for JRuby on Windows

v1.9.0

Add support for JRuby on Windows

Add Support for Ruby 2.3 on Windows

v1.8.0

Add support for Ruby 2.3 on Windows

Use the latest builds on Windows and validate versions

• Fixes #10
• Validate the versions available on Windows by having a list of versions and URLs from the RubyInstaller website.

Use a newer OpenSSL for Ruby 2.3

• Using OpenSSL 1.0.2u instead of OpenSSL 1.0.2q for Ruby 2.3 Ubuntu & macOS builds.
  See eregon/ruby-build#1 and rbenv/ruby-build#1397.

• Ruby >= 2.4 Ubuntu & macOS use the system OpenSSL.