Nighlies are failing

Nighlies are failling.

https://gitlab.idiap.ch/bob/bob.nightlies/-/jobs/170869 https://gitlab.idiap.ch/bob/bob.nightlies/-/jobs/170870

UNLINKLINKTRANSACTION_CMD
    unlink_link_transaction.execute()
  File "/Users/gitlab/builds/b6d3167a/0/bob/bob.nightlies/miniconda/lib/python3.7/site-packages/conda/core/link.py", line 247, in execute
    self._execute(tuple(concat(interleave(itervalues(self.prefix_action_groups)))))
  File "/Users/gitlab/builds/b6d3167a/0/bob/bob.nightlies/miniconda/lib/python3.7/site-packages/conda/core/link.py", line 634, in _execute
    target_prefix)
  File "/Users/gitlab/builds/b6d3167a/0/bob/bob.nightlies/miniconda/lib/python3.7/site-packages/conda/core/link.py", line 1196, in run_script
    raise LinkError(message)
conda.exceptions.LinkError: pre-link script failed for package http://www.idiap.ch/software/bob/conda::bob.db.ijba-2.0.3-py_0
location of failed script: /Users/gitlab/builds/b6d3167a/0/bob/bob.nightlies/miniconda/pkgs/bob.db.ijba-2.0.3-py_0/bin/.bob.db.ijba-pre-link.sh

For some reason the nightlies is trying to get the test dependency bob.db.ijba 2.0.3 from the STABLE channel (not the beta one). Such version is no longer available.

    bob.db.gbu:                    2.1.8b0-py36hbfee937_37   local                                 
    bob.db.ijba:                   2.0.3-py_0                http://www.idiap.ch/software/bob/conda
    bob.db.ijbc:                   1.0.2b0-py36h25400a2_37   local                                 

We should consider to move this dependency up in the build order. I know ijba depends on bob.bio.base for one specific feature, but we could switch this feature off.