Modification in authorize/3, and implemented capture

1. Used commit for HTTPoison requests.
2. Handled network and arguement errors.
3. Updated docs

lib/gringotts/gateways/mercadopago.ex

@@ -177,101 +177,7 @@ defmodule Gringotts.Gateways.Mercadopago do
     commit(:put, url, body, headers) |> respond(opts)
   end
 
-  @doc """
-  Transfers `amount` from the customer to the merchant.
-
-  mercadopago attempts to process a purchase on behalf of the customer, by
-  debiting `amount` from the customer's account by charging the customer's
-  `card`.
-
-  ## Example
-
-  The following example shows how one would process a payment worth 42 BRL in
-  one-shot, without (pre) authorization.
-
-      iex> amount = Money.new(42, :BRL)
-      iex> card = %Gringotts.CreditCard{first_name: "Harry", last_name: "Potter", number: "4200000000000000", year: 2099, month: 12, verification_code:  "123", brand: "VISA"}
-      iex> {:ok, purchase_result} = Gringotts.purchase(Gringotts.Gateways.Mercadopago, amount, card, opts)
-      iex> purchase_result.token # This is the customer ID/token
-
-  """
-  @spec purchase(Money.t, CreditCard.t(), keyword) :: {:ok | :error, Response}
-  def purchase(amount, %CreditCard{} = card, opts) do
-    if Keyword.has_key?(opts, :customer_id) do
-      auth_token(amount, card, opts, opts[:customer_id], true)
-    else
-      {state, res} = get_customer_id(opts)
-      if state == :error do
-        {state, res}
-      else
-        auth_token(amount, card, opts, res, true)
-      end
-    end
-  end
-
-  @doc """
-  Voids the referenced payment.
-
-  This method attempts a reversal of a previous transaction referenced by
-  `payment_id`.
-
-  > As a consequence, the customer will never see any booking on his statement.
-
-  ## Note
-
-  > Only pending or in_process payments can be cancelled.
-
-  > Cancelled coupon payments, deposits and/or transfers will be deposited in the buyer’s Mercadopago account.
-
-  ## Example
-
-  The following example shows how one would void a previous (pre)
-  authorization. Remember that our `capture/3` example only did a partial
-  capture.
-
-      iex> {:ok, void_result} = Gringotts.void(Gringotts.Gateways.Mercadopago, auth_result.id, opts)
 
-  """
-  @spec void(String.t(), keyword) :: {:ok | :error, Response}
-  def void(payment_id, opts) do
-    url = "#{@base_url}/v1/payments/#{payment_id}?access_token=#{opts[:config][:access_token]}"
-    headers = [{"content-type", "application/json"}]
-    body = %{"status": "cancelled"} |> Poison.encode!
-    commit(:put, url, body, headers) |> respond(opts)
-  end
-
-  @doc """
-  Refunds the `amount` to the customer's account with reference to a prior transfer.
-
-  mercadopago processes a full or partial refund worth `amount`, referencing a
-  previous `purchase/3` or `capture/3`.
-
-  ## Note
-
-  > You must have enough available money in your account so you can refund the payment amount successfully. Otherwise, you'll get a 400 Bad Request error.
-
-  > You can refund a payment within 90 days after it was accredited.
-
-  > You can only refund approved payments.
-
-  > You can perform up to 20 partial refunds in one payment.
-
-  ## Example
-
-  The following example shows how one would (completely) refund a previous
-  purchase (and similarily for captures).
-
-      iex> amount = Money.new(35, :BRL)
-      iex> {:ok, refund_result} = Gringotts.refund(Gringotts.Gateways.Mercadopago, purchase_result.id, amount)
-  """
-  @spec refund(Money.t, String.t(), keyword) :: {:ok | :error, Response}
-  def refund(payment_id, amount, opts) do
-    {_, value, _, _} = Money.to_integer_exp(amount)
-    url = "#{@base_url}/v1/payments/#{payment_id}/refunds?access_token=#{opts[:config][:access_token]}"
-    body = %{"amount": value} |> Poison.encode!
-    headers = [{"content-type", "application/json"}]
-    commit(:post, url, body, headers) |> respond(opts)
-  end
 
 
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