update bytebuffer collections dep to fix issue with empty spatial concise sets
Merge branch 'master' of github.com:metamx/druid
prepare for next release
[maven-release-plugin] prepare release druid-0.6.159
[maven-release-plugin] prepare for next development iteration
add a best practices doc
simplify test for approx histogram
remove unused test code
fix groupBy ordering casing bug
Merge pull request #790 from metamx/fix-groupby-order-casing

fix casing issue when specifying ordering dimension in groupBy
fix rollup for hashed partitions

truncate timestamp while calculating the partitionNumber
Add test for bucket selection
Merge pull request #791 from metamx/fix-rollup-hashed-partitions

Fix rollup hashed partitions
Merge pull request #4 from metamx/master

merge to local master