add k-means parfor test
add k-means parfor test

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