Added basic monica docker deployment.
A key which is required for monica is automatically generated on
deployment.
Optionally, geolocation and weather api can be enabled.
Mail-sending functionality is disabled by default but can be enabled
with any compatible smtp server set up.
If a domain has been declared for the host, the upstream file will proxy
at a subdomain named for the stack it proxies to,
otherwise it will do the same for the path.
Added variable docker_swarm_advertise_addr which can be set to the
advertise address swarm should use.
Mostly introduced for vagrant-based test setups for now, which contain
multiple IP addresses and fail otherwise.