File permissions are clobbered during the packaging step

[pdsarin]

Hi!

When this component packages files for deployment, it doesn't preserve file permissions. That's an issue for the go lambda runtime as the lambda handler is an executable that needs execution permissions.

I wrote a patch here but I'm submitting this issue before putting in a pull request, per the contribution guidelines. I tested by running the unit tests and by verifying that execution permissions were preserved. Happy to send up a PR or to add additional tests, with a little guidance.