Docker image build on CircleCI (#29932)
Summary:
the source are copied from https://github.com/pytorch/pytorch-ci-dockerfiles, added .circleci/docker/build_docker.sh to start building job with circleci specific variables.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/29932
Differential Revision: D18645740
Pulled By: mingbowan
fbshipit-source-id: 15fdec85ce59f72daa418ac59792535fed1d136b
