Webmockの仕様変更に対応したspecの修正

[45deg]

rspec によるテストを実行した際、17個のサンプルにおいて失敗しました。
実行環境: ruby 2.2.0p0, webmock 1.21.0

80 examples, 17 failures

Failed examples:

rspec ./spec/rakuten_web_service/books/genre_spec.rb:40 # RakutenWebService::Books::Genre.search call the endpoint once
rspec ./spec/rakuten_web_service/books/genre_spec.rb:43 # RakutenWebService::Books::Genre.search has interfaces like hash
rspec ./spec/rakuten_web_service/books/genre_spec.rb:47 # RakutenWebService::Books::Genre.search has interfaces like hash with snake case key
rspec ./spec/rakuten_web_service/books/genre_spec.rb:51 # RakutenWebService::Books::Genre.search has interfaces to get each attribute
rspec ./spec/rakuten_web_service/books/genre_spec.rb:85 # RakutenWebService::Books::Genre.root alias of constructor with the root genre id "000"
rspec ./spec/rakuten_web_service/books/genre_spec.rb:98 # RakutenWebService::Books::Genre#children When get search method are Books::Genre objects
rspec ./spec/rakuten_web_service/books/genre_spec.rb:107 # RakutenWebService::Books::Genre#children when the genre object has no children information call the endpoint to get children
rspec ./spec/rakuten_web_service/books/genre_spec.rb:124 # RakutenWebService::Books::Genre#search if the genre_id starts with "001" delegate Books::Book.search
rspec ./spec/rakuten_web_service/books/genre_spec.rb:134 # RakutenWebService::Books::Genre#search if the genre_id starts with "002" delegate Books::CD.search
rspec ./spec/rakuten_web_service/books/genre_spec.rb:144 # RakutenWebService::Books::Genre#search if the genre_id starts with "003" delegate Books::DVD.search
rspec ./spec/rakuten_web_service/books/genre_spec.rb:154 # RakutenWebService::Books::Genre#search if the genre_id starts with "004" delegate Books::Software.search
rspec ./spec/rakuten_web_service/books/genre_spec.rb:164 # RakutenWebService::Books::Genre#search if the genre_id starts with "005" delegate Books::ForeignBook.search
rspec ./spec/rakuten_web_service/books/genre_spec.rb:174 # RakutenWebService::Books::Genre#search if the genre_id starts with "006" delegate Books::Game.search
rspec ./spec/rakuten_web_service/books/genre_spec.rb:184 # RakutenWebService::Books::Genre#search if the genre_id starts with "007" delegate Books::Magazine.search
rspec ./spec/rakuten_web_service/kobo/genre_spec.rb:36 # RakutenWebService::Kobo::Genre.search call the endpoint once
rspec ./spec/rakuten_web_service/kobo/genre_spec.rb:48 # RakutenWebService::Kobo::Genre#search Without arguments should call RWS::Kobo::Ebook.search with specifying genre id
rspec ./spec/rakuten_web_service/kobo/genre_spec.rb:55 # RakutenWebService::Kobo::Genre#search With arguments should call RWS::Kobo::Ebook.search with given arguments and genre id

該当部分の spec ファイルを調査したところ、webmockの仕様変更により挙動が変わっていたようです（ bblimke/webmock#427 ）。そのため、specのbefore部分でエラーが発生し、テストに通らないという事態が発生していました。

修正したので、マージをお願いします。

[satoryu]

💯

[koichiro]

💯 でました 🎉

[satoryu]

LGTM