def payment_detail(payment_id)
      payment_id = payment_id.payment_id if payment_id.instance_of? Instamojo::Payment
      get("payments/#{payment_id}")
      @response.success? ? Instamojo::Payment.new(@response.body[:payment], self) : @response
    end
def payment_detail(payment_id)
      payment_id = payment_id.payment_id if payment_id.instance_of? Instamojo::Payment
      get("payments/#{payment_id}")
      @response.success? ? Instamojo::Payment.new(@response.body[:payment], self) : @response
    end
GET /payments/:payment_id