PDIO-237 Fix TrainingTestSplit for non-rate action
PDIO-239 Eliminate duplicates in output when both freshness and serendipity are non-zero
PDIO-242 Change action name 'buy' to 'conversion' in admin UI
PDIO-240 add try catch for accessing array element in mahout data prep and capture error data
PDIO-241 Disallow \t in itypes
Bump to version 0.6.3
Merge branch 'hotfix-0.6.3'