systemd support about ansible-hubot

[emanuelis]

Simple template:

[Unit]
Description=Hubot

[Service]
EnvironmentFile={{ hubot_dir }}/{{ hubot_identity }}.env
User={{ hubot_admin }}
ExecStart={{ hubot_dir }}/bin/start-hubot

[Install]
WantedBy=multi-user.target

[brianshumate]

Not a huge systemd fan here 😄 and versions of Ubuntu prior to 15.04 use Upstart by default.

That said, I'll go ahead and add it since it would certainly be useful.

Thanks!