Set up CI with Azure Pipelines (#22839)
Summary:
Introduce Azure Pipelines for the linting checks. This is meant to be equivalent to the existing Travis linting phase.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22839
Differential Revision: D16260376
Pulled By: ezyang
fbshipit-source-id: 1e535c3096358be67a0dad4cd920a92082b2d18e
