update loxigen-artifacts

Pulls in bsn_role_status and bsn_controller_connections.
update indigo

* submodules/indigo cf28cd1...88c8151 (1):
  > Merge into master from pull request #77: BSN role status and controller query implementations (https://github.com/floodlight/indigo/pull/77)
Merge into master from pull request #83:
update indigo and loxigen-artifacts (https://github.com/floodlight/ivs/pull/83)