Bump parent's version to the current one

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Release version 3.4

This commit marks version 3.4, and once merged into 'master', Jenkins will
pick it up and build and deploy the stable version:

	http://jenkins.imagej.net/job/Sholl-Analysis/

Of course, the plan is to change the version to 3.4.1-SNAPSHOT as soon as
Jenkins ran successfully...

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Merge pull request #2 from fiji/master

Set release version 3.4.0 in pom.xml