Migrate to mocha@8

[coveralls]

Pull Request Test Coverage Report for Build 365

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.7%) to 96.491%

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Files with Coverage Reduction	New Missed Lines	%
src/main/js/log/index.js	1	92.68%
<!--	Total:	1		-->

Totals
Change from base Build 363:	-0.7%
Covered Lines:	437
Relevant Lines:	443

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💛 - Coveralls

[qiwibot]

:tada: This PR is included in version 2.4.2 :tada:

The release is available on:

• v2.4.2
• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot :package::rocket: