Last call for src:chipmunk maintenance

[Simon McVittie <smcv@debian.org>]

src:chipmunk is a shared library that isn't currently used by anything
in Debian and hasn't had an upload since 2013.

If you have a use for this package, please upload the pending changes from
games-team git (see #900448). Updating from upstream version 6 to 7 would
probably also be valuable, although it's likely to be significant work.

Otherwise, I will ask for it to be removed from Debian on or after
2020-05-01 (that's in 2 weeks' time).

Thanks,
    smcv