fix api blog error

[sgratzl]

see https://github.com/cmu-delphi/www-main/runs/2040846791?check_suite_focus=true

[sgratzl]

I assume it is because:

Fetching covid_ag_raw_pct_positive from quidel for 2020-08-01 to 2020-08-01 in geography 'ny': no results

@krivard can you update the code to work again?

related code chunk:

www-main/content/blog/2020-08-28-api.Rmd

Lines 285 to 302 in 689ceda

	```{r q-versioning, warning=FALSE, message=FALSE, cache=TRUE}
	library(covidcast)
	library(dplyr)
	query_date <- "2020-08-01"
	covidcast_signal(
	data_source = "quidel",
	signal = "covid_ag_raw_pct_positive",
	start_day = query_date,
	end_day = query_date,
	geo_type = "state",
	geo_value = "ny",
	issues = c(query_date, "2020-09-04")) %>%
	select(time_value, value, sample_size, issue, lag) %>%
	distinct(value, .keep_all=TRUE) %>%
	knitr::kable("html", digits = 2,
	col.names = c("Test date", "Positivity rate (%)", "Sample size",
	"Issued on", "Lag (days)"))
	```

[krivard]

This is probably due to BIGINT -- the only issues we have for 2020 are the latest issue for each day, so if that falls outside of the queried range it won't return anything.

We're still looking for a way to restore the 2020 data history that will complete before May but doesn't require taking down COVIDcast for 2 days.

[sgratzl]

are there any workaround in which we could change the blog post? it is getting annoying that half my CI build fail

[sgratzl]

see also cmu-delphi/covidcast#519

#295 is disabling the problematic line for now. However, I won't update the rendered HTML page. Thus, the published blog looks the same. Once either the big int issue has been resolved we can enable it again