avoid query to user when inst/doc occupied?

[vjcitn]

is it possible to avoid this situation?:

> rcmdcheck::rcmdcheck("parody")
── R CMD build ─────────────────────────────────────────────────────────────────
Building the package will delete...
  '/private/tmp/parody/inst/doc'
Are you sure?

1: Yes
2: No

I can't quite tell where this query is coming from -- but it doesn't happen for R CMD check. I would
like to be able to set an option that allows deletion of the contents in inst/doc without approval.

[gaborcsardi]

I think this is a duplicate of #130