fluview_clinical queries return duplicate results

[pedritom-amzn]

problem: fluview_clinical queries seem to always return duplicate results, even accounting for the same release date.

from dfarrow0@ offline:

I checked, and can confirm they are duplicated in the database. I think is is not supposed to be this way. I suspect problem with unique key constraint.

impact: if customers don't expect duplicates, their usage of the data may be incorrect.

proposal: if the duplicates are unexpected, fix the bug causing them. if they are expected, update the documentation for this source to make it clear to customers.

---

example: https://delphi.midas.cs.cmu.edu/epidata/api.php?source=fluview_clinical&regions=nat&epiweeks=202001 currently returns:
{"result":1,"epidata":[{"release_date":"2020-04-13","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-16","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-11","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-14","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-12","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-15","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-10","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-14","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-11","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-15","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-13","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-16","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-10","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-14","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-11","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461},{"release_date":"2020-04-15","region":"nat","issue":202014,"epiweek":202001,"lag":13,"total_specimens":64980,"total_a":5651,"total_b":9647,"percent_positive":23.5426,"percent_a":8.69652,"percent_b":14.8461}],"message":"success"}
notice, for example, the row for release_date 2020-04-14 occurs 3 times.

[dmytrotsko]

Fixed