Add an article or two for covering cassette management

[maelle]

• When to delete a cassette and re-record it. (maybe in the debugging article? an out-of-date cassette is a common reason for test failure after all)

• how and why to edit your cassettes by hand or with a script with the yaml package

  • to test for error behavior without having to learn webmockr
  • to test for sequence of requests (e.g. 502 then 200) without having to learn webmockr
  • if you edit a cassette you might want to add skip_if_vcr_off().
  • we imagine you will edit cassette by hand but you could also imagine writing a script to make your edits reproducible (using the yaml package if your cassettes are YAML; using jsonlite if your cassettes are JSON). However it might be more work than it's worth; editing cassettes by hand is perfectly fine.

[sckott]

That sounds good.

[maelle]

added a section about deleting cassettes in the debugging vignette PR

[maelle]

I will work on a vignette about editing cassettes by hand once #195 because the skipper is needed when you edit cassettes by hand.

[sckott]

ok, thanks