Don't override the default per_page in Grape APIs

By leaving the default per_page setting in Grape APIs as nil,
ApiPagination intercepts it later and uses the paginator's default
per_page setting instead. Fixes #47.

Signed-off-by: David Celis <[email protected]>

Author: davidcelis

lib/grape/pagination.rb

@@ -33,7 +33,7 @@ def paginate(collection)
 
       base.class_eval do
         def self.paginate(options = {})
-          route_setting :per_page, (options[:per_page] || 25)
+          route_setting :per_page, options[:per_page]
           route_setting :max_per_page, options[:max_per_page]
           params do
             optional :page,     :type => Integer, :default => 1,