Bump the parent in preparation for version 0.3.0

A couple of issues revolving around the updater have been resolved
recently; some of these fixes involve the updater GUI which now lives in
imagej-ui-swing. Therefore, we bumped the versions for both
imagej-updater and imagej-ui-swing preemptively in pom-imagej.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>