* Find MAC address if mesh.hardware-addr not given
Defaulting to the machine's MAC address fails
sometimes fails and causes a panic. Allow the user
to specify custom address to skip this so they can
run AlertManager.
* -mesh.hardware-address -> -mesh.peer-id
* Fix command-line invocation
This add a Procfile that can be run with `goreman start`. It starts
three Alertmanagers and one webhook receiver. The webhook receiver
simply reflects sent messages.
The send_alerts.sh script simulates a set of alerts sent by a Prometheus
server to all Alertmanagers at once.