Allow defining top-level modules without ::

[k0kubun]

This is a feature originally proposed in itamae-kitchen/mitamae#64, using the idea in https://dev.to/okuramasafumi/eval-ing-twice-to-define-toplevel-module-from-string-33ma.

Instead of module ::Helper, you'll be able to write the following recipes without errors:

# helper.rb
module Helper
  def self.help
    :help
  end
end

# recipe.rb
include_recipe 'helper'
Helper.help

This also fixes #308.

[unasuke]

It seems ok. Ruby is very profound...Ah, where is the result of travis-ci.com?
Last night, we reached the quota of travis ci maybe. sue445-san had contacted travis. I want to wait for the response.

[sue445]

@k0kubun I revived CI and merged the latest master.

But the build seems to be failing.
Please fix this 🙏

[sue445]

LGTM

[k0kubun]

Thanks for preparing GitHub Actions! 👏 👏 👏

[sue445]

released as v1.12.1 🚀