Fix url for composer as a service

README.md

@@ -758,7 +758,7 @@ Libraries to help manage database schemas and migrations.
 * [3V4L](http://3v4l.org/) - An online PHP & HHVM shell.
 * [DBV](http://dbv.vizuina.com/) - A database version control application.
 * [PHP Queue](https://github.com/CoderKungfu/php-queue) - An application for managing queueing backends.
-* [Composer as a Service](http://composer.borreli.com/) - A tool for downloading Composer packages as a zip file.
+* [Composer as a Service](https://composer.borreli.com/) - A tool for downloading Composer packages as a zip file.
 * [MailCatcher](https://github.com/sj26/mailcatcher) - A web tool for capturing and viewing emails.
 * [Cachet](https://github.com/cachethq/cachet) - The open source status page system.