Release PubSubHub v0.0.2

The changelog says it too, but this is a bugfix release to unblock David
as he implements an event with no subscribers yet.

Change-Id: I38bfdbe9da903eaf308a94e35d6df7670185674e
Reviewed-on: https://gerrit.causes.com/33142
Reviewed-by: Shane da Silva <shane@causes.com>
Reviewed-by: David Gouldin <david.gouldin@causes.com>
Tested-by: Tom Dooner <tom.dooner@causes.com>