Change requests from GET to POST
Change requests from GET to POST

See https://github.com/cmu-delphi/covidcast/issues/362
cmu-delphi/delphi-epidata,cmu-delphi/delphi-epidata,cmu-delphi/delphi-epidata,cmu-delphi/delphi-epidata,cmu-delphi/delphi-epidata,cmu-delphi/delphi-epidata