Add debug information in BridgeCreateEvent
Add debug information in BridgeCreateEvent

Added extra information (bridge name) when a bridge creation event
is received.

Trivial fix: changed BridgeCreateEvent __init__ argument to "agent",
as requested in [1].

[1] https://review.openstack.org/#/c/612153/

Partial-Bug: #1789592

Change-Id: I0bca7e71fb379febfe2131566bb8c1bf8f039183

mahak/neutron,noironetworks/neutron,openstack/neutron,mahak/neutron,mahak/neutron,noironetworks/neutron,openstack/neutron,openstack/neutron