A small test refactor to ensure tests that modifies env-vars are not running in parallel.
A small test refactor to ensure tests that modifies env-vars are not running in parallel.

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