add countyCdLookup to readWQPdata and readNWISdata
WQP does not seem to be returning what I would expect with:
dailyStaffordVA <- readWQPdata(statecode = "Virginia", countycode="Stafford",
parameterCd = "00060")
siteInfo <- attr(dailyStaffordVA, "siteInfo)
unique(siteInfo$countycode) # this should be length 1