func authenticate(username: String, password:String, completionHandler: @escaping () -> (), failure: @escaping (_ result:Error) ->()){
    let json = [
        "username" : "(username)",
        "password" : "(password)"
    ]

    Alamofire.request(ApiRouterManager.PostLogin(parameters: json))
        .validate(statusCode: 200..<300)
        .validate(contentType: ["application/json"])
        .responseJSON { response in
            switch response.result{
            case .success:
                completionHandler()
            case .failure(let error):
                failure(error)
            }
    }
}