Merge pull request #915 from xhh/ruby-file-response

[Ruby] Support file downloading for Ruby API client

modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/RubyClientCodegen.java

@@ -61,6 +61,7 @@ public class RubyClientCodegen extends DefaultCodegen implements CodegenConfig {
         typeMapping.put("List", "Array");
         typeMapping.put("map", "Hash");
         typeMapping.put("object", "Object");
+        typeMapping.put("file", "File");
 
         // remove modelPackage and apiPackage added by default
         cliOptions.clear();