Error log numbers don't reset when tests are re-run

[whyboris]

Unsure if this is intended behavior or not:

For example:

• two tests fail with 1) and 2) displaying with their associated errors.
• you edit a file, save, triggering the tests to run again
• when any tests fail (let's say the same two test fail again)
• the numbers accompanying the errors in the error report will say 3) and 4)
• when tests run again, if three tests fail, 5), 6), and 7) will show

The only way to reset the counter is to exit the testing Ctrl + C and restart npm test

Expected behavior:

• Tests' error logged ordered list will always start at 1)

I can happily submit a PR for this; it takes only a few lines of code to fix