Merge pull request #707 from hashicorp/warn-on-duplicates-wrapper

Add functions to replicate old HCL V1 Behavior for backwards compatability

Merge pull request #704 from sarahalsmiller/check-for-duplicates

Update V1 Parser to Check for Duplicates

Merge pull request #694 from hashicorp/prepare-release-2.22.0

Prepare for v2.22.0 release

prepare for v2.21.0 release

Update CHANGELOG for 2.20.1

update CHANGELOG.md for v2.20

Merge pull request #635 from hashicorp/jbardin/WithoutOptionalAttribu…

…tesDeep

hcldec must use WithoutOptionalAttributesDeep