Make Predis\Connection\PhpiredisConnection::write() protected.

We should actually make use of more protected methods in this
class instead of the private ones, this is most likely going
to be addressed in future commits.

See also issue #86 on GitHub for the reason behind this change.

lib/Predis/Connection/PhpiredisConnection.php

@@ -328,7 +328,7 @@ class PhpiredisConnection extends AbstractConnection
     /**
      * {@inheritdoc}
      */
-    private function write($buffer)
+    protected function write($buffer)
     {
         $socket = $this->getResource();