Switch to new payment method endpoints

include/account_subnav.html

@@ -2,7 +2,7 @@
 <nav id="subnav" class="wrapper">
 	<a class="subnav-link" href="/account">Account</a>
 	<a class="subnav-link" href="/account/contact">Contact Info</a>
-	<a class="subnav-link" href="/account/creditcard">Update Credit Card</a>
+	<a class="subnav-link" href="/account/creditcard">Add Credit Card</a>
 	<a class="subnav-link" href="/account/make_a_payment">Make A Payment</a>
 	<a class="subnav-link" href="/account/billing_history">Billing History</a>
 	<a class="subnav-link" href="/user">Users</a>