Tractography constraints metadata currently not informative

[arokem]

I am seeing this:

I think that's because ROIs passed on this line:

pyAFQ/AFQ/tasks/tractography.py

Line 53 in 0e4601c

Constraints=dict(ROI=stop),

are nibabel objects, which cannot be serialized into the JSON. I wonder if we can create an object, which also carries along a file-path or at least the file-name. Not urgent, by any means.

[36000]

Its probably occurring when you use CMC or ACT. we should fix it in #103