pom.xml: use junit 4.13.2
pom.xml: use junit 4.13.2

junit before 4.13.1 is subject to CVE-2020-15250.

Signed-off-by: Heinrich Schuchardt <2cd7bb605d542f55cc27b85da62ad2c96ce31039@gmx.de>

xypron/jcobyla