Allow specifying a different chown user

[nemchik]

https://github.com/rtCamp/action-deploy-wordpress/blob/04f6302b4bbf64b26b3605c0c3800c701bcae20c/deploy.php#L170 This tries to chown files to www-data but that user is not the user I need with my web host. I would like the ability to chown to a different user. In my case, the user specified in the hosts.yml would work fine, but being able to provide the user as an environment variable to the GitHub Action or define the chown user in the hosts.yml file would be nice.