Update aws-cli to v1.17.1

Default to us-east-1 region and clear credentials after sync is done.

bump action to version 0.4.0 and AWS CLI to 1.16.262

Avoid whitespace issues in args with `sh -c`

Clarify latest changes in v0.3.0 in README.md

Bump version to v0.2.0

Update license

better README.md and remove --dry-run