LUCENE-3762: update README to indicate junit 4.10.x
LUCENE-3762: update README to indicate junit 4.10.x

git-svn-id: 308d55f399f3bd9aa0560a10e81a003040006c48@1290830 13f79535-47bb-0310-9956-ffa450edef68

apache/solr,apache/solr,apache/solr,apache/solr,apache/solr