Azure Pipelines - Windows CI (#2729)
Azure Pipelines - Windows CI (#2729)

* Windows CI azure pipeline (to eventually replace appveyor.yml)

* Update Windows CI - combine install and testing scripts

* removing flake8, as it is tested in the other CIs and not included in original pipeline (linux / osx)
onnx/onnx,onnx/onnx,onnx/onnx,onnx/onnx