Add a make_tempdir() utility function to the TestCase base class (#51762)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/51762
Update test_util.py to add a `make_tempdir()` function to the `TestCase`
class. The main advantage of this function is that the temporary
directory will be automatically cleaned up when the test case finishes,
so that test case does not need to worry about manually cleaning up this
directory.
This also prefixes the directory name with `caffe2_test.` so that it is
more obvious where the temporary directories came from if they are ever
left behind after a crashed or killed test process.
This updates the tests in `operator_test/load_save_test.py` to use this
new function, so they no longer have to perform their own manual cleanup
in each test.
Test Plan: python caffe2/python/operator_test/load_save_test.py
Reviewed By: mraway
Differential Revision: D26271178
Pulled By: simpkins
fbshipit-source-id: 51175eefed39d65c03484482e84923e5f39a4768
