Deploy webserver roles on hervil

Summary:
The initial plan was to deploy web applications on Docker PaaS.

Yet, it seems applications like ViMbAdmin can profit from an
existing mail installation locally.

Also, the mailserver role requires PHP for DKIM.

New plan is to consolidate mail services on the same server.

Ref T1932

Test Plan: Apply states to configure the webserver part

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T1932

Differential Revision: https://devcentral.nasqueron.org/D3342