Port tests to mockito 2.x

This change moves test suites to mockito 2 and harmonises on
a single version of hamcrest as well as updating maven plug-ins
where necessary and harmonising on a single version of JDT
annotations (some bundles moved to the newer Java 8+ annotations
since all bundles have a BREE of Java 8+).

Orbit dep updates:
* Mockito 1.9.5 -> 2.23.0
* Hamcrest 1.1 & 1.3 -> 1.3 Only
* Objenesis 1.0.0 -> 2.6.0

Maven updates:
* animal-sniffer-maven-plugin 1.15 -> 1.16

Bug: 546373
Change-Id: I9d24ffff5769631ad70c443d24056212ea8eb5ba
Signed-off-by: Mat Booth <mat.booth@redhat.com>
11 files changed