replace the python covidcast client in SirCAL

[melange396]

covidcast-indicators/sir_complainsalot/delphi_sir_complainsalot/check_source.py

Lines 75 to 80 in 833e818

	latest_data = covidcast.signal(
	data_source, row["signal"],
	start_day=datetime.now() - timedelta(days = 14),
	end_day=datetime.now(),
	geo_type=row["geo_type"]
	)

SirCAL uses the python covidcast client which has some issues including inefficiency, as it makes individual http requests for each of the days in the specified range (and also even in the deprecated asynchronous mode, though they are ~simultaneous).