Update dependencies.

[lijunle]

• Update yargs to 4.x and resolve the help parameter breaking change.
• Update ESLint-Config-Airbnb to 6.x and resolve the warnings.
• However, disable the ESLint rule no-confusing-arrow.

[codecov-io]

Current coverage is 98.06%

Merging #101 into master will decrease coverage by -0.04% as of e081087

@@            master    #101   diff @@
======================================
  Files           16      16       
  Stmts          369     362     -7
  Branches        84      81     -3
  Methods          0       0       
======================================
- Hit            362     355     -7
  Partial          5       5       
  Missed           2       2       

Review entire Coverage Diff as of e081087

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