payment: add support for pagination in PaymentPluginApi#searchPaymentMethods

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>
pom.xml: fix version in subprojects

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>
travis: initial import of travis.yml

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>
Merge remote-tracking branch 'origin/master' into initial-version-of-pagination
pom.xml: update to killbill-oss-parent 0.5.0

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>