v1.3 release Merge changes for v1.3 release

Merge pull request aws#53 from aws/develop Merge changes for v1.2 release

Merge from aws-lambda-runtime-interface-emulator/develop (aws#40) * Pull upstream changes (aws#34) * Pull upstream changes 2021/06 (aws#39) * docs: Fix ordering of options in example (aws#36) Co-authored-by: Jon Colverson <[email protected]>

Fix integ tests (aws#4) Co-authored-by: Jacob Fuss <[email protected]>