Sagemaker

Documentation Changes

* add documentation guidelines to CONTRIBUTING.md
* Removed section numbering

Bug Fixes and Other Changes

* remove NEO_ALLOWED_TARGET_INSTANCE_FAMILY

Documentation Changes

* remove labels from issue templates

Bug Fixes and Other Changes

* account for EI and version-based ECR repo naming in serving_image_uri()

Documentation Changes

* correct broken AutoML API documentation link
* fix MXNet version lists

Bug Fixes and Other Changes

* disable Debugger defaults in unsupported regions
* modify session and kms_utils to check for S3 bucket before creation
* update docker-compose and PyYAML dependencies
* enable smdebug for Horovod (MPI) training setup
* create lib dir for dependencies safely (only if it doesn't exist yet).
* create the correct session for MultiDataModel

Documentation Changes

* update links to the local mode notebooks examples.
* Remove outdated badges from README
* update links to TF notebook examples to link to script mode examples.
* clean up headings, verb tenses, names, etc. in MXNet overview
* Update SageMaker operator Helm chart installation guide

Testing and Release Infrastructure

* choose faster notebook for notebook PR build
* properly fail PR build if has-matching-changes fails
* properly fail PR build if has-matching-changes fails

Bug fixes and other changes

* do not use script for TFS when entry_point is not provided
* remove usage of pkg_resources
* update py2 warning message since python 2 is deprecated
* cleanup experiments, trials, and trial components in integ tests