Validator throws exception on non-string default values for model properties

This will cause an error in the validator
http://online.swagger.io/validator/debug?url=

{
  "properties" : {
    "success" : {
      "type" : "boolean",
      "default" : false
    }
  }
}

But this is ok:

{
  "properties" : {
    "success" : {
      "type" : "boolean",
      "default" : true
    }
  }
}

And so is this:

{
  "properties" : {
    "success" : {
      "type" : "boolean",
      "default" : "false"
    }
  }
}

Start with the validator debug URL and the three JSON examples in the issue, comparing boolean false with boolean true and the string "false" as default values. Reproduce the failure, trace the validator's handling of model-property defaults, and consider the issue done when valid non-string defaults no longer throw an exception and the contrasting examples behave consistently.