Add export-historic-test-times option to dump S3 test times into a JSON file (#54083)
Summary:
This will allow for future work to use the test times file (which will save computation time and also allow for more consistency). (Step one to fixing https://github.com/pytorch/pytorch/issues/53882)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/54083
Test Plan:
export CIRCLE_JOB=your-favorite-circleci-job e.g., pytorch_linux_xenial_cuda10_2_cudnn7_py3_gcc7_test2
`python test/run_test.py --export-historic-test-times` OR
`python test/run_test.py --export-historic-test-times .your-favorite-file`
When opening either .pytorch-test-times or .your-favorite-file, you should see something like:
```
{"commit": "2d559a09392aabb84dfb4a498010b2f01d99818c", "job_times": {"distributed/test_distributed_spawn": 583.5889999999973, "distributed/test_data_parallel": 4.866999999999997, "test_binary_ufuncs": 171.1569999999998, "test_numpy_interop": 2.5649999999999995, "test_public_bindings": 0.011,...}}
```
Note that no tests will be run when this option is specified.
Reviewed By: walterddr
Differential Revision: D27091351
Pulled By: janeyx99
fbshipit-source-id: e191d739268d86de0a0ba0eea0006969859d1940
