Add functionality for checking status codes of a response

[IIVat]

It would be very helpful to check a status codes of a response with methods :

@Lenses case class Status(code: Int, text: String, description: String) {
  def isInformational: Boolean = this.code / 100 == 1
  def isSuccess: Boolean = this.code / 100 == 2
  def isRedirection: Boolean = this.code / 100 == 3
  def isClientError: Boolean = this.code / 100 == 4
  def isServerError: Boolean = this.code / 100 == 5
}

[pepegar]

fixed in #112