This function adds
httptest to Suggests in the package DESCRIPTION and
loads it in
tests/testthat/helper.R. Call it once when you're setting up
a new package test suite.
use_httptest(path = ".")
character path to the package
Nothing: called for file system side effects.
The function is idempotent: if
httptest is already added to these files, no
additional changes will be made.