Can we have an option to prevent the library from installing DynamoDB local?

[vamsiampolu]

In setup, the library checks to see if DynamoDB local is already running and only installs if the dynamodb local is not running and the directory ${os.tmpdir()}/dynamodb-local is not setup correctly. I'd like an option that allows the user to explicitly disallow the library from downloading the jar.

This would allow users like me to keep using their existing dynamodb setup like this docker image while using this preset to setup and teardown tables.

[vladholubiev]

PRs are welcome! I don't mind having such an option in the library