make prune only removes this project's volumes

[gluckzhang]

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What does this implement/fix? Explain your changes.

Adjust the Makefile and let make prune only delete the volumes created by this docker-compose project. The following command works:

docker volume prune -f --filter label=com.docker.compose.project=elastic

Does this close any currently open issues?

Yes, this closes #72 .

Any relevant logs, error output, etc?

Not necessary in this case.

Where has this been tested?

In my local environment.

[sherifabdlnaby]

@gluckzhang Thank you for finding and fixing this one! 🙏🏻