Given a card map, creates a card token.

Returns a tuple

{:ok,
%{card: %{address_city: "Hogwarts", address_country: "Straya",
   address_line1: "The Game Keepers Cottage", address_line2: nil,
   address_postcode: "H0G", address_state: "WA", customer_token: nil,
   display_number: "XXXX-XXXX-XXXX-0000", expiry_month: 10, expiry_year: 2016,
   name: "Rubius Hagrid", primary: nil, scheme: "visa",
   token: "card_hK8nB6YEyDQKz0swg8C_6Q"}}}

OR

{:error, error_map}