Add checks for hashing on Py2.
Add checks for hashing on Py2.

As title.

stonebig/numba,sklam/numba,cpcloud/numba,stonebig/numba,stonebig/numba,IntelLabs/numba,jriehl/numba,IntelLabs/numba,gmarkall/numba,gmarkall/numba,gmarkall/numba,sklam/numba,cpcloud/numba,numba/numba,cpcloud/numba,seibert/numba,stuartarchibald/numba,stuartarchibald/numba,gmarkall/numba,stuartarchibald/numba,IntelLabs/numba,numba/numba,sklam/numba,stonebig/numba,IntelLabs/numba,numba/numba,seibert/numba,cpcloud/numba,gmarkall/numba,stuartarchibald/numba,numba/numba,seibert/numba,cpcloud/numba,seibert/numba,seibert/numba,jriehl/numba,jriehl/numba,jriehl/numba,stonebig/numba,numba/numba,sklam/numba,IntelLabs/numba,sklam/numba,jriehl/numba,stuartarchibald/numba