Test runner CLI - zinnia test

[bajtos]

Add a new CLI command zinnia test for running the tests.

Examples to consider

Run all tests in the current project:

❯ zinnia test

Run all tests in a single file:

❯ zinnia test path/to/file.js

Run all tests matching a given pattern:

❯ zinnia test --filter "a substring or a regexp"

Notes

• Ideally, this should allow us to remove the final line Error: Uncaught [some test(s) failed] printed as a side effect of setting the process exit code to a non-zero value.