Setup Deployment Pipeline

[xiazhvera]

1. Added the scripts for python SDK deployment. The deployment pipeline has the following stages
   a. Verify the package version. Check if we need push a new release

   • continuous-delivery/test_version_exists.yml
   • continuous-delivery/test_version_exists
     b. Deliver to Test pypi and test
   • continuous-delivery/publish_to_test_pypi.yml
   • continuous-delivery/test_test_pypi.yml
     c. Publish to prod pypi
   • continuous-delivery/publish_to_prod_pypi.yml
   • continuous-delivery/test_prod_pypi.yml

2. Added "--print_discover_resp_only" flag for greengrass sample. The flag is used for deployment test only, once the flag is set, the program always return true as long as the SDK API is imported correctly

3. setup_test.py
   The setup file is for test deployment only. Since the package name is already used in another account, for the test pypi, we use a different package name.

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[bretambrose]

Ideally we should delete that empty Credentials directory but would need to verify that the integration tests don't give an error if the directory is used during the run and needs to exist.