fix null stats
merging with fix_null_stats branch
Merge branch 'master' of https://github.com/Parquet/parquet-mr into stats
Bug fix - resetting stats after writing page. Fixed unit test to test reading footer
Cleaning up + testing small & large values
Merge pull request #399 from egonina/stats

Fixed resetting stats after writePage bug, unit testing of readFooter
[maven-release-plugin] prepare release parquet-1.5.0
[maven-release-plugin] prepare for next development iteration