Revert "minor #1410 Update testing.rst - preventing Fatal Error: Class...

Revert "minor #1410 Update testing.rst - preventing Fatal Error: Class 'Silex\WebTestCase' not found (Czarnodziej)"

This reverts commit af39ead0, reversing
changes made to a102df4d.

doc/testing.rst

@@ -192,7 +192,6 @@ look like this:
              processIsolation="false"
              stopOnFailure="false"
              syntaxCheck="false"
-             bootstrap="vendor/autoload.php"
     >
         <testsuites>
             <testsuite name="YourApp Test Suite">