Vagrant provision update: add `sendmail` and configure for mailing

[kamataryo]

I wanted for the Mapwarper instance on Vagrant to send emails but not sent. Rails console described absence of package sendmail.

Devise::Mailer#confirmation_instructions: processed outbound mail in 742.5ms
sh: 1: /usr/sbin/sendmail: not found

This PR contains a few points on Vagrant machine provisioning for mail sending debugging.

I am sorry that the trailing space fixations make unclear which lines were essentially fixed. The lines are below.

• sendmail installation: https://github.com/timwaters/mapwarper/compare/master...KamataRyo:vagrant-provision-with-sendmail?expand=1#diff-04c6e90faac2675aa89e2176d2eec7d8R68
• set FQDN hostname: https://github.com/timwaters/mapwarper/compare/master...KamataRyo:vagrant-provision-with-sendmail?expand=1#diff-23b6f443c01ea2efcb4f36eedfea9089R20
• configuration for mail delivery debugging: https://github.com/timwaters/mapwarper/compare/master...KamataRyo:vagrant-provision-with-sendmail?expand=1#diff-a2f09e1db7a47eb67c5849478a97f3d7R19

[timwaters]

maybe if you could redo this with just the two files that would be great, also I don't think we should change the development environment as by default it shouldn't raise mailing errors in dev mode.

Developers can look in the log to see the content of emails.

[kamataryo]

Thank you for always commenting! I understood that and reverted the development environment to default.

[kamataryo]

This pull request now become legacy.