chore(ps): add code coverage reports

[zwhitfield3]

Why the change?

GUS Card

As per our review of unit tests and coverage for the ps package, this PR does the following:

• Adds nyc package to add code coverage reports ✅
• Ensures that our code coverage reports over 85% test coverage of statements ✅

Additional Notes

• No additional test failure scenarios to include. Incorrect user inputs have been accounted for.

How to verify?

1. Pull down branch
2. Run tests
3. Confirm test coverage report is visible and that it reports over 85% test coverage of statements

[kenyaplenty]

Everything looks good to me in terms of the code, but when I run yarn test in the package, I get the following output after the code coverage report. Is there something wrong with my setup? Is this supposed to be happening?

[zwhitfield3]

@kenyaplenty I turned off the explicit-module-boundary-types rule that looks for an explicit return statement in the run functions for the cli commands. The framework doesn't require return statements for the run function in commands as per oclif documentation examples.

As for the support typescript versions, we'll have to update the typescript-estree dependency in a few other command dependencies at a later date. It is not blocking for this PR.

[kenyaplenty]

LGTM