New oauth cache files are not added to .gitignore, .Rbuildignore

[jennybc]

If cache = TRUE or cache = "some/path" (vs NA) in httr::oauth2.0_token(), a newly created .httr-oauth file is NOT in fact added to .gitignore and .Rbuildignore. This is contrary to the documentation and, I think?, behaviour at some point in the past. Update: I now think httr has always been this way.

The failure to .gitignore is the bigger problem and has lead to some googlesheets users committing and pushing tokens to GitHub (googlesheets sets cache = TRUE by default).