MongoDBStORM is not JSONConvertible

[truemetal]

I can simply add the following to make it comply. Since this is pretty much boilerplate, good idea is to add it to MongoDBStORM or StORM itself

func jsonEncodedString() throws -> String
{
        let obj:[String:Any] = ["key1":value, "key2":value, "key3":value]
        let data = try JSONSerialization.data(withJSONObject: obj, options: [])
        if let json = String(data: data, encoding: .utf8) { return json }
        throw NSError(domain: "failed to create json string", code: 0, userInfo: nil)
}