hg: jigsaw/jake/hotspot: Bump jtreg requiredVersion to 4.2

[mandy . chung]

Changeset: 425a05d96c09
Author:    mchung
Date:      2016-03-15 12:00 -0700
URL:       http://hg.openjdk.java.net/jigsaw/jake/hotspot/rev/425a05d96c09

Bump jtreg requiredVersion to 4.2

! test/TEST.ROOT