Use /usr/sbin/nologin as login shells for vmail and znc users
Merge pull request #283 from lvillani/nologin

Merge pull request #283
Install ZNC Monit config file only when needed

This commit moves the monitoring role to the bottom of site.yml so that
it is executed after all other roles.

This is needed because the monitoring role conditionally installs Monit
configuration file based on whether some other packages have been
installed or not (such as ZNC).

This patch also adds a comment to the "monitoring" entry within the
"roles" list and a `roles/monitoring/README.md` file telling users why
the monitoring role has to come last.

Resolves #284
Add support for Thunderbird automatic configuration

Resolves #114
Merge pull request #288 from lvillani/issue-284

Merge pull request #288
Merge pull request #287 from lvillani/thunderbird-autoconfig

Merge pull request #287
Make sure fail2ban is started