feat(swagger-object): name of instance is now compliant with instance directive when instance name is retrieved from class name

Author: MathiusD

src/swagger/object.cr

@@ -24,7 +24,7 @@ module Swagger
 
     def self.create_from_instance(reflecting instance : T, custom_name : String? = nil, refs : Hash(String, (String | self))? = nil) forall T
       {% begin %}
-        instance_name = custom_name ? custom_name.as(String) : instance.class.name
+        instance_name = custom_name ? custom_name.as(String) : instance.class.name.gsub("::") {"_"}
         properties = [] of Property
         {% for ivar in T.instance.instance_vars %}
           {{ iname = ivar.name.stringify }}