Define IID_IUnknown is lutinUtils rather than in polka

3 jobs for master in 6 minutes and 20 seconds (queued for 3 seconds)
Name Stage Failure
failed
test_opam_test Test There is an unknown failure, please try again
  - install ocamlfind     1.7.3     
- install ocamlify 0.0.1
- install ocamlmod 0.0.9
- install ounit 2.0.6
- install rdbg 1.156

The former state can be restored with:
opam switch import "~/.opam/4.05.0/backup/state-20171113220925.export"
ERROR: Job failed: exit code 1