`dub remove --non-interactive` will now remove all packages by default

When calling a command with a package name and no version specification,
the latest version is usually assumed.
While this behavior makes sense for `dub fetch` or `dub run`,
it can come  as a surprise when cleaning up local packages through `dub remove`,
and so previous version would simply error out when more than one version was available.
From this version, `dub remove -n $PKGNAME` will just remove all cached versions
of the package named `$PKGNAME`, without asking you to use `$PKGNAME@*`.