Create a home page notification when the credit card details are missing

cc-notification.html

{% if current_account %}
  {% if current_account.credit_card_required? and current_account.credit_card_missing? %}
    <div class="missing_card">
      <p>You have selected a paid API plan. 
      Please <a href="{{ urls.payment_details }}">enter your credit card</a> 
      to get access to your API key.</p>
    </div>
  {% endif %}
{% endif %}