feat: support custom node version based on engines

[kentcdodds]

What: feat: support custom node version based on engines (falls back to node version 8).

Why: So projects can more easily specifically target the version they need to support.

How: Using semver and getting the engines.node property in the package.json to determine the oldest version supported and transpile down to that.

Checklist:

• Documentation N/A 😅
• Tests N/A 😅
• Ready to be merged
• Added myself to contributors table N/A

[codecov]

Codecov Report

Merging #66 into master will decrease coverage by 0.71%.
The diff coverage is 33.33%.

@@            Coverage Diff             @@
##           master      #66      +/-   ##
==========================================
- Coverage    72.6%   71.89%   -0.72%     
==========================================
  Files          21       21              
  Lines         365      370       +5     
  Branches       81       82       +1     
==========================================
+ Hits          265      266       +1     
- Misses         79       82       +3     
- Partials       21       22       +1

Impacted Files	Coverage Δ
src/config/babelrc.js	77.77% <33.33%> (-22.23%)	⬇️

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[kentcdodds]

🎉 This PR is included in version 0.44.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀