feat: allow ordering by case expression

[doug-martin]

• Allow ordering by case expressions

[codecov]

Codecov Report

Merging #292 (1d55a36) into master (ce33bd7) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #292   +/-   ##
=======================================
  Coverage   96.80%   96.81%           
=======================================
  Files          61       61           
  Lines        3353     3355    +2     
=======================================
+ Hits         3246     3248    +2     
  Misses         91       91           
  Partials       16       16           

Flag	Coverage Δ
unittests	96.81% <100.00%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
exp/exp.go	67.14% <ø> (ø)
exp/case.go	100.00% <100.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update ce33bd7...1d55a36. Read the comment docs.