pom.xml: updates for release 0.78
pom.xml: updates for release 0.78

Update killbill-commons -> 0.12

Signed-off-by: Kill Bill core team <1a73af9e7ae00182733b2292511b814be66f065f@killbill.io>

rocketlawyer/killbill-oss-parent,killbill/killbill-oss-parent