Module novaclient.v1_1 is used as implementation of V1.1, V2 and V3.
Since future development(microversioning) will be done across V2,
implementation should be done in appropriate module(to prevent misleading).
Despite the fact that implementation for all versions are equal, discover
method for contrib path worked only for v1.1. This patch fixes this bug and
modifies shell tests to check all versions.
This adds support for the os-server-external-events extension in nova,
which allows other services to deliver events to nova.
It also adds a shell command to trigger the "network-changed" event
manually, which will cause nova to refresh its network cache from
Related to blueprint admin-event-callback-api