[Feature Request] Save to specific folder, and only certain files to cover

[tomardern]

Hi,

Great work on the pupeteer-to-instanbul work - first found this repo after watching a Google IO talk.

It would be nice to:

• Save the files to a specific folder (rather than a .nyc_output)
• Some kind of filter/callback function so that files can be renamed (or ignored) before saving. This is especially useful if a site includes tracking scripts which do not need to have a coverage report

Thanks!

[vkoves]

Great suggestions! I don't think I'll be able to take this on myself in the near future, but I've labelled it to hopefully allow it to get some attention

[aadityataparia]

After #25, You can provide options to change outputFile and give a function that filters files.