Fix lintian E: source-ships-excluded-file

Current debian/sid contains vendor/*.

It should not be bundled.

Repack archive and import it. uscan command helps you to repack.

$ uscan --download-current-version

Then, import generated archive again.

$ gbp import-orig ../(generated archive)

After that, edit debian/changelog version to 0.9.4+ds-1. (We need to discuss further more about appropriate versioning)