[maven-release-plugin] prepare release 0.20

git-svn-id: https://svn.apache.org/repos/asf/rave/trunk@1442332 13f79535-47bb-0310-9956-ffa450edef68
[maven-release-plugin] prepare for next development iteration

git-svn-id: https://svn.apache.org/repos/asf/rave/trunk@1442334 13f79535-47bb-0310-9956-ffa450edef68