v2.4.0

• Convert everything to Ruby 1.9 syntax because I'm tired of people removing trailing commas despite the massive warning in the README: (#29, #30, #32, #33, #34, #35, #36, #38, #39)
• Update to the latest and greatest testing gems and practices
• Remove strainer in favor of a purer solution
• Update .gitignore to ignore additional files
• Add more platforms to the .kitchen.yml
• Use converge_by and support whyruny mode