upgrade to Lucene 2.9.1
upgrade to Lucene 2.9.1

ehealthafrica-ci/couchdb-lucene,eHealthAfrica/couchdb-lucene,rnewson/couchdb-lucene,ehealthafrica-ci/couchdb-lucene,eHealthAfrica/couchdb-lucene,ehealthafrica-ci/couchdb-lucene,rnewson/couchdb-lucene,rnewson/couchdb-lucene,eHealthAfrica/couchdb-lucene