Remove win32console requirement in ruby 2.0.0 and higher

[Darunada]

This allows ansi to color output in windows with ruby 2+ without attempting to load win32console

The win32console gem is no longer required for ruby 2 or higher in Windows.
See: luislavena/win32console#17 (comment)

[Darunada]

The CI check seems to fail because it's using an outdated version of bundler.

See: rubygems/bundler#3559

[thomthom]

Would it be possible to get this PR merged? A few gems depend on this ansi gem and on Windows it's often no color output as a result.

[thomthom]

For anyone else (or myself in the future) that might be looking for ways to address the issue of ansi not using color on Windows, here is an example of how I made minitest-reporters work:

# test_helper.rb

# Kludge: minitest-reporter depend on the `ansi` gem which hasn't been updated
# for a very long time. It's expecting to use another `win32console` gem in
# order to provide colorized output on Windows even though that is not longer
# needed. This works around that by fooling Ruby to think it has been loaded.
#
# https://github.com/rubyworks/ansi/issues/36
# https://github.com/rubyworks/ansi/pull/35
$LOADED_FEATURES << 'Win32/Console/ANSI'
Minitest::Reporters.use!