Do we need pynwb - if yes please care for its new dependency

Hi Yaroslav,

I bumped pynwb to its latest upstream version a couple of times.  It was
not release in any stable release since o-o-stable since the package was
always in a bad state.  Popcon is pretty low[1] - but we do not see any
Ubuntu users here so may be that's a weak metric.

My recent update in Git to latest upstream has uncovered that it needs
a new predepends[2].  If you consider this package a good citizen inside
Debian it would be great if you would care for this new package.  Other
bugs should be fixed in Salsa, thought.

Kind regards
    Andreas.

[1] https://qa.debian.org/popcon.php?package=pynwb
[2] https://github.com/NeurodataWithoutBorders/nwb-schema