We sometimes run into rate-limiting issues

[njtierney]

Sometimes the tests fail due to rate limiting issues when downloading files using download_survey(). It seems that perhaps the zenodo servers have been a bit busy lately. It has been hard to replicate, but I have tried to improve this by using rate throttling via purrr::insistently() in contactsurveys: epiforecasts/contactsurveys#80

[sbfnk]

With this function deprecated this is no longer an issue (at least not in this repo).