Turn integration test into a maven-failsafe-plugin based one

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge branch 'it-failsafe'

Now that scijava-common 1.6.2 is released, we can merge this branch
(because it requires CheckSezpoz to run correctly on test-classes, too).

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