Add Dockerfile to support unit testing alarm-go

This dockerfile installs the prerequisites to compile the alarm-go
library and run the golang unit tests.
Add logging statements to dump AlarmMessage as struct and as marshalled
to JSON.
Add JSON schema that can be used to validate payloads.

Signed-off-by: Lott, Christopher (cl778h) <cl778h@att.com>
Change-Id: Ib46c524e2e0593124f79be64afa23847612897c8