* Adding in some functionality to use different clouds

This support is needed for the air gapped environments.  There are three
ways to add a new cloud environment.  These were all taken from examples
in the v1 sdk.

1) The SDK will look for a default configuration file and try to find
   cloud environments in there.
2) If you set an environment variable called ARM_METADATA_URL, it will
   look there for cloud configurations.  If you do not set this, it will
   use a default URL in the _azure_environments.py file to find them.
3) The SDK exposes two new functions, add_cloud which will add the new
   configuration to the configuration file mentioned in #1, and
   update_cloud which will update the added configuration.

* Removing some of the functionality, only ARM check remains

* Adding unit test for new environments functionality

* fixed tests with mock

* removed print statement

* removed commented code

* removed print statements (oops)

* fixed tests and removed comments

* Fixing a testing bug

* Fixing a misspelled word

* Changing how we reach out to ARM, als fixing some pylint

* Fixing more lint errors

* Fixing more lint errors

* updated code per suggestions in PR

* fixed typo in warning

* added registry_endpoint to metadata url, also added tests for making sure all endpointurls are registered

* updated how the registry discovery endpoint is created. Uses a default region but region can be updated with environment variable

* fixed linting errors

* moved discovery url logic around to make sure it's not overwriting public regions

* Fixing small pylint errors

* Moving over to using HttpPipeline instead of requests

* fixed up based on comments in the PR

* fixed broken unit tests and mocked correctly

* Fixing pylint issues

---------

Co-authored-by: Ronald Shaw <ronaldshaw@microsoft.com>

* Update with new swagger

* changes for job matching modes

* remove generated models
- all models have been handcoded

* fix lint errors #1

* fix lint errors 2

* update swagger to point to main specs repo