Support required in JSON scheme draft v4

[wsalembi]

In draft v4 the required property is defined on the object level and not on the property level.

JSON scheme v3 is currently supported and generated @NotNull annotations:

{
  "type":"object",
  "properties": {
    "foo": {
      "type": "string"
    },
    "bar": {
      "type": "integer",
      "required" : true
    },
    "baz": {
      "type": "boolean"
    }
  }
}

JSON scheme v4 is not supported

{
  "type":"object",
  "properties": {
    "foo": {
      "type": "string"
    },
    "bar": {
      "type": "integer"
    },
    "baz": {
      "type": "boolean"
    }
  },
  "required" : ["type"]
}

[joelittlejohn]

This has actually just been fixed by pull request #325, it will be released in the next version (0.4.11).