WHY IS THIS CHANGE NEEDED?:
- grouper (which usues chainer) breaks if it accesses a channel that is
  not GFP

HOW DOES THE CHANGE SOLVE THE PROBLEM?:
- chainer assumes all experiments have a GFP channel; this was
  hard-coded in line 29 in chainer.py

WHAT SIDE EFFECTS DOES THIS CHANGE HAVE?:
- yet to test

EVIDENCE THAT COMMIT WORKS:
- pipelines pending

REFERENCES:
- ...