Release 3.0.0

  - Use Rack builder to shorten and simplify the code
  - Add support for namespaces by using the builder
  - Add ruby-prof as a development dependency
  - NYNY will return a Rack-like response on each request ([status, headers, body])
  - headers behave like a hash
  - cookies behave like a hash
  - added sprockets integration example
  - improved documentation