Added options to unlink function
Added options to unlink function

puts('Unlink Number from a Campaign')
response = api.campaign.number_unlink("C9PDW4R", 
                                    "14845071195", 
                                    url: "http://plivobin.non-prod.plivops.com/1j8rc5g1", 
                                    method: "POST")
plivo/plivo-ruby