ACCUMULO-913 update LICENSE file

git-svn-id: https://svn.apache.org/repos/asf/accumulo/branches/1.5@1483559 13f79535-47bb-0310-9956-ffa450edef68
ACCUMULO-913 merge to trunk

git-svn-id: https://svn.apache.org/repos/asf/accumulo/trunk@1483562 13f79535-47bb-0310-9956-ffa450edef68