model: introduce new payment tables

Tests are still passing but semantics around payments still
need to be re-worked.

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>
pom.xml: update to latest killbill-oss-parent

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>
Merge branch 'master' of github.com:killbill/killbill-analytics-plugin