Update Argo_impossible_date_test.py
Update Argo_impossible_date_test.py

Updated the test description to say that the year criterion is not as described in the Argo documentation.
s-good/AutoQC,IQuOD/AutoQC,castelao/AutoQC,BillMills/AutoQC,BillMills/AutoQC,IQuOD/AutoQC,s-good/AutoQC