Add the test workflow. (#729)
Summary:
This PR is to add the testing linux.2xlarge runner to pytorch/benchmark.
Pull Request resolved: https://github.com/pytorch/benchmark/pull/729
Reviewed By: seemethere
Differential Revision: D33905554
Pulled By: xuzhao9
fbshipit-source-id: 1034b4a2c50e467d708884de03a324a4fcb1f1f7