chore: Remove tap and switch to node test runner

[timogasda]

Issue #, if available:

Description of changes: Our test runner tap was causing some dependency warnings. I figured we don't really need to bring in a whole dependency for the tiny test suite we have in this package. So I propose we switch to the NodeJS test runner :)

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[timogasda]

Closing this because the test runner is still experimental and codecov doesn't understand the generated coverage report.