This commit adds a new directory called /snap which contains
the packaging for the edgexfoundry snap.  The snap builds and
includes all of the microservices from the mono-repo, as well
as the two Java-based supports services and device-virtual.
The snap also includes consul, mongodb, and the Java-based
core-config-seed.

Signed-off-by: Tony Espy <espy@canonical.com>