Create a new bionic image with clang9 (#36187)
Summary:
New images are already available at http://docker.pytorch.org/pytorch.html.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/36187
Differential Revision: D21011545
Pulled By: ailzhang
fbshipit-source-id: 4fe98fa63110cb2ecb0194d4a8878fe9d2193611
