Updated mail config comments from postmark to mailgun

app/config/mail.php

@@ -24,7 +24,7 @@ return array(
 	|
 	| Here you may provide the host address of the SMTP server used by your
 	| applications. A default option is provided that is compatible with
-	| the Postmark mail service, which will provide reliable delivery.
+	| the Mailgun mail service, which will provide reliable delivery.
 	|
 	*/
 
@@ -37,7 +37,7 @@ return array(
 	|
 	| This is the SMTP port used by your application to delivery e-mails to
 	| users of your application. Like the host we have set this value to
-	| stay compatible with the Postmark e-mail application by default.
+	| stay compatible with the Mailgun e-mail application by default.
 	|
 	*/