Update README.md (#4427)
Update README.md (#4427)

Co-authored-by: Sang Ik Lee <aa6563a7b56e5ef7f7ffa08e0bc60e65c5df68a1@intel.com>
Co-authored-by: Scott Cyphers <7bb9a997e5f2906b81b1e1515637af43501e2590@users.noreply.github.com>
NervanaSystems/ngraph,NervanaSystems/ngraph,NervanaSystems/ngraph,NervanaSystems/ngraph