pom.xml: remove SNAPSHOT dependency
pom.xml: remove SNAPSHOT dependency

Signed-off-by: Pierre-Alexandre Meyer <ff019a5748a52b5641624af88a54a2f0e46a9fb5@mouraf.org>

killbill/killbill-hello-world-java-plugin,trifonnt/killbill-java-plugin-two-servlets,fathomstudio/killbill-bluepay-plugin,fathomstudio/killbill-bluepay-plugin