Ruby client tests don't pass

There are some issues with the generated Rudy specs.

Steps to reproduce

brew install swagger-codegen
swagger-codegen generate -i https://petstore.swagger.io/v2/swagger.json -l ruby -o client
cd client
bundle install
rspec

Error

An error occurred while loading ./spec/base_object_spec.rb.
Failure/Error:
  class ArrayMapObject < Petstore::Category
    attr_accessor :int_arr, :pet_arr, :int_map, :pet_map, :int_arr_map, :pet_arr_map, :boolean_true_arr, :boolean_false_arr

    def self.attribute_map
      {
        :int_arr => :int_arr,
        :pet_arr => :pet_arr,
        :int_map => :int_map,
        :pet_map => :pet_map,
        :int_arr_map => :int_arr_map,

NameError:
  uninitialized constant Petstore
# ./spec/base_object_spec.rb:3:in `<top (required)>'


Finished in 0.00004 seconds (files took 0.50225 seconds to load)
0 examples, 0 failures, 1 error occurred outside of examples

Generate the Ruby client with the documented swagger-codegen command, install its bundle, and run rspec to reproduce the failure in spec/base_object_spec.rb. Trace why the generated spec cannot resolve Petstore, then verify that the complete Ruby client test suite loads and runs without this error.