Add support for other config['mailer'] options.

[apple314159]

PHPMailer supports other mailer options such as Mail, Qmail, and sendmail.
Tested with sendmail.

[lcharette]

Related #776 ? Setting up sendmail as default, at least for Vagrant install, could be helpful. I'll have to check what email support Homestead as installed by default.

Either way, adding an env config for this would be nice too.

[apple314159]

I don't use Vagrant or Homestead.

In our setup, our email server is on another machine. I wanted to queue email locally using sendmail to not block PHP.

[lcharette]

Just make sure everything is aligned correctly according to PSR rules. not sure about that case place... Might be wrong too.

[lcharette]

@alexweissman That if (isset($config['mailer'])) {... In the original code, if no  mailer was defined, the exception wasn't thrown. Was that intended? Otherwise, the switch will work fine if that ìfis not there, but the hpmailerException` will always be thrown if there's no config thrown.

Original : https://github.com/apple314159/UserFrosting/blob/master/app/sprinkles/core/src/Mail/Mailer.php#L46
Modified: https://github.com/apple314159/UserFrosting/blob/ccda4012456f0ea7aec6f6b110805c5736d0f622/app/sprinkles/core/src/Mail/Mailer.php#L46

[lcharette]

Merged manually in f67e358 for the develop branch. Will be released in 4.2; Thanks !