ignore dependency:unpack inside m2e

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>
maven 3.2.4 compatibility

sadly, there does not appear a way to use Guava Stopwatch that will
will with maven <3.2.4 (Guava 14.0.1) and 3.2.4 (Guava 18.0).

Signed-off-by: Igor Fedorenko <igor@ifedorenko.com>