[BUG] Doesn't load or run under Ruby 2.7.8

[walterdavis]

Describe the bug
Trying to follow the README ends in a failed include error.

To Reproduce
Steps to reproduce the behavior:

1. Run chelsea --file ./Gemfile.lock
2. See error: cannot load such file -- ox/ox (LoadError)

Expected behavior
I was hoping to see a report, as documented in the README.

Desktop (please complete the following information):

• OS: Mac OS 13.3 (22E252)
• Ruby Version: 2.7.8
• Bundler Version: 2.4.10
• chelsea Version 0.0.35

Additional context
This happens whether the ox and chelsea gems are in the bundle, and chelsea is invoked with bundle exec or not.

Here is a trace of the error:

waldavis@PMACS-DEV-134 mannequin % chelsea --file ./Gemfile.lock
Traceback (most recent call last):
	19: from /Users/waldavis/.rvm/gems/ruby-2.7.8/bin/ruby_executable_hooks:22:in `<main>'
	18: from /Users/waldavis/.rvm/gems/ruby-2.7.8/bin/ruby_executable_hooks:22:in `eval'
	17: from /Users/waldavis/.rvm/gems/ruby-2.7.8/bin/chelsea:25:in `<main>'
	16: from /Users/waldavis/.rvm/gems/ruby-2.7.8/bin/chelsea:25:in `load'
	15: from /Users/waldavis/.rvm/gems/ruby-2.7.8/gems/chelsea-0.0.35/bin/chelsea:20:in `<top (required)>'
	14: from /Users/waldavis/.rvm/gems/ruby-2.7.8/gems/chelsea-0.0.35/bin/chelsea:20:in `require_relative'
	13: from /Users/waldavis/.rvm/gems/ruby-2.7.8/gems/chelsea-0.0.35/lib/chelsea.rb:20:in `<top (required)>'
	12: from /Users/waldavis/.rvm/gems/ruby-2.7.8/gems/chelsea-0.0.35/lib/chelsea.rb:20:in `require_relative'
	11: from /Users/waldavis/.rvm/gems/ruby-2.7.8/gems/chelsea-0.0.35/lib/chelsea/cli.rb:24:in `<top (required)>'
	10: from /Users/waldavis/.rvm/gems/ruby-2.7.8/gems/chelsea-0.0.35/lib/chelsea/cli.rb:24:in `require_relative'
	 9: from /Users/waldavis/.rvm/gems/ruby-2.7.8/gems/chelsea-0.0.35/lib/chelsea/gems.rb:26:in `<top (required)>'
	 8: from /Users/waldavis/.rvm/gems/ruby-2.7.8/gems/chelsea-0.0.35/lib/chelsea/gems.rb:26:in `require_relative'
	 7: from /Users/waldavis/.rvm/gems/ruby-2.7.8/gems/chelsea-0.0.35/lib/chelsea/formatters/factory.rb:20:in `<top (required)>'
	 6: from /Users/waldavis/.rvm/gems/ruby-2.7.8/gems/chelsea-0.0.35/lib/chelsea/formatters/factory.rb:20:in `require_relative'
	 5: from /Users/waldavis/.rvm/gems/ruby-2.7.8/gems/chelsea-0.0.35/lib/chelsea/formatters/xml.rb:19:in `<top (required)>'
	 4: from /Users/waldavis/.rvm/rubies/ruby-2.7.8/lib/ruby/site_ruby/2.7.0/rubygems/core_ext/kernel_require.rb:85:in `require'
	 3: from /Users/waldavis/.rvm/rubies/ruby-2.7.8/lib/ruby/site_ruby/2.7.0/rubygems/core_ext/kernel_require.rb:85:in `require'
	 2: from /Users/waldavis/.rvm/gems/ruby-2.7.8/gems/ox-2.13.4/lib/ox.rb:79:in `<top (required)>'
	 1: from /Users/waldavis/.rvm/rubies/ruby-2.7.8/lib/ruby/site_ruby/2.7.0/rubygems/core_ext/kernel_require.rb:85:in `require'
/Users/waldavis/.rvm/rubies/ruby-2.7.8/lib/ruby/site_ruby/2.7.0/rubygems/core_ext/kernel_require.rb:85:in `require': cannot load such file -- ox/ox (LoadError)
waldavis@PMACS-DEV-134 mannequin % gem info ox

*** LOCAL GEMS ***

ox (2.13.4)
    Author: Peter Ohler
    Homepage: http://www.ohler.com/ox
    License: MIT
    Installed at: /Users/waldavis/.rvm/gems/ruby-2.7.8

    A fast XML parser and object serializer.
waldavis@PMACS-DEV-134 mannequin % gem info chelsea

*** LOCAL GEMS ***

chelsea (0.0.35)
    Author: Allister Beharry
    Homepage: https://github.com/sonatype-nexus-community/chelsea
    License: Apache-2.0
    Installed at: /Users/waldavis/.rvm/gems/ruby-2.7.8

    Audit Ruby package dependencies for security vulnerabilities.