Run mocha tests in parallel
Run mocha tests in parallel

The new [parallel tests] feature of Mocha v8 runs each test file in
parallel.  This is a nice performance benefit for packages with multiple
test files on multi-core machines.

[parallel tests]: https://mochajs.org/#parallel-tests

Signed-off-by: Kevin Locke <ffb4761cba839470133bee36aeb139f58d7dbaa9@kevinlocke.name>

kevinoid/swagger-spec-validator,kevinoid/promised-read,kevinoid/node-project-template,kevinoid/appveyor-status,kevinoid/node-project-template,kevinoid/stream-compare,kevinoid/appveyor-status,kevinoid/promised-read,kevinoid/swagger-spec-validator,kevinoid/git-branch-is,kevinoid/git-branch-is,kevinoid/stream-compare,kevinoid/node-project-template,kevinoid/appveyor-status,kevinoid/swagger-spec-validator,kevinoid/stream-compare,kevinoid/promised-read,kevinoid/travis-status,kevinoid/travis-status,kevinoid/git-branch-is,kevinoid/travis-status