Fix requiring path of bootstrap.php in external processes spawned by tests.

test/PredisShared.php

@@ -79,7 +79,7 @@ class RC {
         $redisUri = sprintf('redis://%s:%d/?database=%d', RC::SERVER_HOST, RC::SERVER_PORT, RC::DEFAULT_DATABASE);
         $handle = popen('php', 'w');
         fwrite($handle, "<?php
-        require 'bootstrap.php';
+        require __DIR__.'/test/bootstrap.php';
         \$redis = new Predis\Client('$redisUri');
         \$redis->rpush('{$op}1', 'a');
         \$redis->rpush('{$op}2', 'b');