MailExtension: add support for context param (#39)

you can add param context for more specific configuration, eg.
mail:
	smtp: true
	...
	secure: ssl
	context:
		ssl:
			verify_peer: false
			verify_peer_name: false

Author: podolinek

src/Bridges/MailDI/MailExtension.php

@@ -26,6 +26,7 @@ class MailExtension extends Nette\DI\CompilerExtension
 		'password' => NULL,
 		'secure' => NULL,
 		'timeout' => NULL,
+		'context'  => NULL,
 	];