Cloudformation-cli-go-plugin

Support protocol version 2.0.0 to response the handler result with callback directly and allow CloudFormation service to orchestrate the callback.

It will resolve several resource limits:

- Resource model limit: 16K -> 6M
- Resource re-invoke payload: 8K -> 6M
- Resource max stabilization time : 12H -> 36H

adding `sam-tests/` to initially generated default `.gitignore`: https://github.com/aws-cloudformation/cloudformation-cli-go-plugin/pull/144

Releasing latest fixes that unblock registrations with new protocolVersion.

Releasing latest changes. Includes fix when using latest version of the cloudformation-cli.

Releasing the latest changes. Includes fixes to contract testing and metrics.

Latest release of the cloudformation-cli-go-plugin. Makes some naming changes due to repository rename as well as other improvements around calling back to CloudFormation.