Remove credit card samples (#896)

* removed credit card payment samples
* update docs to reflect sample changes
* update readme to recommend braintree for direct card payments

sample/payments/GetCapture.php

@@ -4,19 +4,19 @@
 // of a captured payment.
 // API used: /v1/payments/capture/<$captureId>
 
-/** @var Capture $request */
-$request = require 'AuthorizationCapture.php';
-
 use PayPal\Api\Capture;
 
+// Replace $captureId with any static Id you might already have. 
+$captureId = "<your authorization id here>";
+
 // ### Retrieve Capture details
 // You can look up a capture by invoking the Capture::get method 
 // with a valid ApiContext (See bootstrap.php for more on `ApiContext`)
 try {
-    $capture = Capture::get($request->getId(), $apiContext);
+    $capture = Capture::get($captureId, $apiContext);
 } catch (Exception $ex) {
     // NOTE: PLEASE DO NOT USE RESULTPRINTER CLASS IN YOUR ORIGINAL CODE. FOR SAMPLE ONLY
-    ResultPrinter::printError("Get Captured Payment", "Capture", $request->getId(), null, $ex);
+    ResultPrinter::printError("Get Captured Payment", "Capture", $captureId, null, $ex);
     exit(1);
 }