FIX: Pass new variable args as kwargs in split()

[effigies]

SimpleVariable.__init__ does not take a run_info parameter, while SparseRunVariable.__init__ does. Further, the order of the other variables is inconsistent, so subclassing works poorly. The fix in #353 used positional arguments, which worked for SparseRunVariable, but failed for SimpleVariable. This fix uses kwargs to avoid the ordering problem. Because SparseRunVariable.__init__ accepts a **kwargs parameter and does nothing with it, this is safe.

Related to #352/#353. I think there was another issue where I ran into this, but I can't find it right now.

Cherry-picked from #376.

[codecov]

Codecov Report

Merging #386 into master will decrease coverage by 0.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #386      +/-   ##
==========================================
- Coverage   73.79%   73.78%   -0.02%     
==========================================
  Files          23       23              
  Lines        2492     2491       -1     
  Branches      621      621              
==========================================
- Hits         1839     1838       -1     
  Misses        471      471              
  Partials      182      182

Flag	Coverage Δ
#unittests	73.78% <100%> (-0.02%)	⬇️

Impacted Files	Coverage Δ
bids/variables/variables.py	88.39% <100%> (-0.06%)	⬇️

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[codecov]

Codecov Report

Merging #386 into master will decrease coverage by 0.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #386      +/-   ##
==========================================
- Coverage   73.79%   73.78%   -0.02%     
==========================================
  Files          23       23              
  Lines        2492     2491       -1     
  Branches      621      621              
==========================================
- Hits         1839     1838       -1     
  Misses        471      471              
  Partials      182      182

Flag	Coverage Δ
#unittests	73.78% <100%> (-0.02%)	⬇️

Impacted Files	Coverage Δ
bids/variables/kollekshuns.py	83.57% <100%> (ø)	⬆️
bids/variables/io.py	75.12% <100%> (ø)	⬆️
bids/analysis/transformations/compute.py	86.66% <100%> (ø)	⬆️
bids/variables/variables.py	88.39% <100%> (-0.06%)	⬇️

---

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[tyarkoni]

LGTM, thanks!

[tyarkoni]

Oh, one other thought though: I recall there being other places where we pass positional arguments to variable inits rather than keyword args. I'm generally in favor of using keyword args throughout the codebase, so if you haven't already, it might be worth a quick sweep to see if there are other places the same changes make sense.

[effigies]

Just went ahead and mass-changed to kwarg-only calls.