Fix RHL transform to always use dev version, use new RHL API for website

[alangpierce]

This fixes an issue where sucrase.io wasn't applying the transform right within
Babel because its environment was set to production.

Also switch website RHL usage to the new API that apparently works better.

[codecov-io]

Codecov Report

Merging #386 into master will decrease coverage by 0.05%.
The diff coverage is n/a.

@@            Coverage Diff            @@
##           master    #386      +/-   ##
=========================================
- Coverage   79.86%   79.8%   -0.06%     
=========================================
  Files          45      45              
  Lines        5159    4937     -222     
  Branches     1147    1147              
=========================================
- Hits         4120    3940     -180     
+ Misses        739     699      -40     
+ Partials      300     298       -2

Impacted Files	Coverage Δ
src/util/getNonTypeIdentifiers.ts	75% <0%> (-25%)	⬇️
src/parser/index.ts	77.77% <0%> (-7.94%)	⬇️
src/index.ts	82.85% <0%> (-6.51%)	⬇️
src/computeSourceMap.ts	83.33% <0%> (-5.56%)	⬇️
src/parser/plugins/types.ts	90% <0%> (-4.45%)	⬇️
src/util/getTSImportedNames.ts	81.57% <0%> (-3.79%)	⬇️
src/parser/tokenizer/readWord.ts	82.35% <0%> (-3.02%)	⬇️
src/parser/traverser/util.ts	86.2% <0%> (-2.17%)	⬇️
src/parser/traverser/base.ts	95.45% <0%> (-1.69%)	⬇️
src/parser/traverser/lval.ts	97.01% <0%> (-0.55%)	⬇️
... and 13 more

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