Updates to Sample Code

- Updated UI Presentation on samples
- Fixed Bugs

sample/invoice/ListInvoice.php

@@ -14,9 +14,8 @@ try {
     // Refer the method doc for valid values for keys
     // (See bootstrap.php for more on `ApiContext`)
     $invoices = Invoice::get_all($apiContext);
-} catch (PayPal\Exception\PPConnectionException $ex) {
-    echo "Exception:" . $ex->getMessage() . PHP_EOL;
-    var_dump($ex->getData());
+} catch (Exception $ex) {
+    ResultPrinter::printError("Lookup Invoice History", "Invoice", null, null, $ex);
     exit(1);
 }
 ResultPrinter::printResult("Lookup Invoice History", "Invoice", null, null, $invoices);