add support for allowableValues and defaultValues
add allowedValues and defaultValues + remove format
add responseClass, tags, models support
Merge commit '15dadc5' into fix

* commit '15dadc5':
  add responseClass, tags, models support
  add allowedValues and defaultValues + remove format
  add support for allowableValues and defaultValues

Conflicts:
	lib/grape-swagger.rb
simplify DSL around response_class and models_used
update grape dependency 0.3.0