Fix formatting in package.json
Simplify region disclaimer
Add tests for CloudSearch 2013-01-01 API
Updated list of supported services
Add Samus to Gemfile
Tag release v2.0.0-rc13

References:
  #158, #202, #215, #221, #224, #225, #226, #229, #230, #233,
  #237, #241, #242, #246, #248