handle multiple presents

[AntoineGst]

Handle the multiple present with swagger.
relates to : #776

Exemple :
You need to pass as parameter, to correctly generate the properties :

desc 'Get multiple presents',
             success: [
               { model: Entities::EnumValues, as: :gender },
               { model: Entities::Something, as: :somethings, is_array: true }
             ]

And this generate the swagger schema like this :

{
   "schema":{
      "type":"object",
      "properties":{
         "gender":{
            "$ref":"#/definitions/EnumValues"
         },
         "somethings":{
            "type":"array",
            "items":{
               "$ref":"#/definitions/Something"
            }
         }
      }
   }
}

[coveralls]

Coverage increased (+0.009%) to 99.585% when pulling 9916bb2 on AntoineGuestin:feat_multiple_presents into 8d245e5 on ruby-grape:master.

[LeFnord]

thanks @AntoineGuestin … this is a very welcome PR,
but please can you add a section in the README, similar to your description here, thanks again 😄

[AntoineGst]

Hi @LeFnord,
I add a section in the README ;)

[LeFnord]

👍 … thanks