Merge pull request #230 from rjurney/master

Fixing bug where twitter example does not run.
[maven-release-plugin] prepare release druid-0.5.48
[maven-release-plugin] prepare for next development iteration
Adjust maven assembly so that the tarballs are not released to our artifactory on release.
Merge pull request #231 from rjurney/master

Removed zk references from realtime config
1) Add unit test for groupBy query with dimension that doesn't exist
2) Fix group by query to work with new unit test, fixes #232
Merge branch 'master' of github.com:metamx/druid
[maven-release-plugin] prepare release druid-0.5.49
[maven-release-plugin] prepare for next development iteration
Changed port number for realtime server from 8080 to 8083 to make the exaxmples work with the new realtime config.