Advice to use `Sys.setenv('TESTTHAT_MAX_FAILS' = Inf)` should be clickable

[DavisVaughan]

i.e. here

testthat/R/reporter-progress.R

Line 211 in 0f24eae

"Increase this number with (e.g.) `Sys.setenv('TESTTHAT_MAX_FAILS' = Inf)`"