Add ability to invalidate cloudfront cache on sync

[darraghmckay]

• Invalidate cache: Add optional Cloudfront invalidation step at the end jakejarvis/s3-sync-action#32
• Update arguments to clear warnings: https://github.com/jakejarvis/s3-sync-action/pull/34/files

Currently the files are syncing correctly but cloudfront is caching the index.html which is causing users to download the old .js files. This will allow us to invalidate the cache if we provide a Cloud Front distribution Id

[sowmitranalla]

Thank you for doing this! I liked the original action but this piece was missing 👍

[JaimeKetchum]

Appreciate this - thank you!