Add create card for an existing customer

lib/stripe/cards.ex

@@ -0,0 +1,48 @@
+defmodule Stripe.Cards do
+  @moduledoc """
+  Main API for working with Cards at Stripe. Through this API you can:
+  - create
+
+  (API ref https://stripe.com/docs/api#subscriptions)
+  """
+  @endpoint "customers"
+
+  @doc """
+  Create a card for the specified customer.
+
+  ## Example
+
+  ```
+    new_card = [
+      source: token,
+      metadata: [
+      ...
+      ]
+    ]
+    {:ok, card} = Stripe.Cards.create customer_id, new_card
+  ```
+  """
+  def create(customer_id, opts) do
+    create customer_id, opts, Stripe.config_or_env_key
+  end
+
+  @doc """
+  Create a card for the specified customer using given api key.
+
+  ## Example
+
+  ```
+    new_card = [
+      source: token,
+      metadata: [
+      ...
+      ]
+    ]
+    {:ok, card} = Stripe.Cards.create customer_id, new_card
+  ```
+  """
+  def create(customer_id, opts, key) do
+    Stripe.make_request_with_key(:post, "#{@endpoint}/#{customer_id}/sources", key, opts)
+    |> Stripe.Util.handle_stripe_response
+  end
+end

test/stripe/card_test.exs

@@ -0,0 +1,41 @@
+defmodule Stripe.CardTest do
+  use ExUnit.Case
+
+  #these tests are dependent on the execution order
+  # ExUnit.configure w/ seed: 0 was set
+  setup_all do
+    Stripe.Customers.delete_all
+    customer = Helper.create_test_customer "card_test1@localhost"
+    on_exit fn ->
+      Stripe.Customers.delete customer.id
+    end
+
+    {:ok, [customer: customer]}
+  end
+
+
+  @tag disabled: false
+  test "Create w/opts  works", %{customer: customer} do
+    token = Helper.create_test_token
+    opts = [
+      source: token.id
+    ]
+    case Stripe.Cards.create customer.id, opts do
+      {:ok, card}   -> assert card.customer == customer.id
+      {:error, err} -> flunk err
+    end
+  end
+
+  @tag disabled: false
+  test "Create w/opts w/key works", %{customer: customer} do
+    token = Helper.create_test_token
+    opts = [
+      source: token.id
+    ]
+    case Stripe.Cards.create customer.id, opts, Stripe.config_or_env_key do
+      {:ok, card}   -> assert card.customer == customer.id
+      {:error, err} -> flunk err
+    end
+  end
+
+end

test/test_helper.exs

@@ -19,6 +19,19 @@ defmodule Helper do
     Stripe.Plans.delete "test-dlx"
   end
 
+  def create_test_token do
+    params = [
+      card: [
+        number: "4242424242424242",
+        exp_month: 8,
+        exp_year: 2016,
+        cvc: "314"
+      ]
+    ]
+    {:ok, token} = Stripe.Tokens.create(params)
+    token
+  end
+
   def create_test_customer( email ) do
     new_customer = [
       email: "#{email}",