Add pplbench beanmachine model (#869)
Summary:
Code for integrating beanchmachine pplbench with torchbench
**Outputs:**
_python run.py pplbench_beanmachine -d cpu -t eval_
Running eval method from pplbench_beanmachine on cpu in eager mode.
CPU Total Wall Time: 98.262 milliseconds
_python run.py pplbench_beanmachine -d cpu -t train_
Running train method from pplbench_beanmachine on cpu in eager mode.
CPU Total Wall Time: 16629.886 milliseconds
Pull Request resolved: https://github.com/pytorch/benchmark/pull/869
Reviewed By: xuzhao9
Differential Revision: D35760061
Pulled By: agunapal
fbshipit-source-id: 54dbfc2e2e411f917314b1819df92f37e6a0f5c9
