fix for #610, merged models

Author: fehguy

modules/swagger-core/src/main/scala/com/wordnik/swagger/core/util/ReaderUtil.scala

@@ -24,7 +24,8 @@ trait ReaderUtil {
     val grouped = tuples.groupBy(_._1)
     (for (group <- grouped) yield {
       val apiDescriptions = (for(g <- group._2; api <- g._2.apis) yield api).toList
-      group._2(0)._2.copy(apis = apiDescriptions)
+      val models = (for(g <- group._2; models <- g._2.models) yield models).flatten.toMap
+      group._2(0)._2.copy(apis = apiDescriptions, models = Option(models))
     }).toList
   }
 }