Bump tutorials to latest pom-imagej parent

This fixes many ImageJ bugs, some of which surface relating to the
tutorials. For example, the using-ops tutorial could not show image
objects produced by ops using the ij.ui().show method.
UsingOps: compute larger demo images
UsingOps: display the image in an ImageJ window

It is only natural to want to do this. Until 2.0.0-rc-8 there were bugs
in ImageJ preventing it from working, but now we can finally do it.