* Enable running PEP8 checks via flake8 as part of the build if flake8 is installed.
Update scripts in \tools and \onnxruntime\python. Excluding \onnxruntime\python\tools which needs a lot more work to be PEP8 compliant. Also excluding orttraining\tools for the same reason.
Install flake8 as part of the static_analysis build task in the Win-CPU CI so the checks are run in one CI build.
Update coding standards doc.
* Add a helper script to more easily create a test directory for use with onnx_test_runner or onnxruntime_perf_test.
Add example script that can be used as a base for performance testing a model with a variety of input sizes.
Add __init__.py so files in this directory can be imported in other scripts.
* Fix some flake8 warnings.
Add example of specifying attribute for op.
* Add ability for test dir creation to fill in all missing input data with random values.
Add example of using test dir creation this way