Fix for checkstyle.
Fixed #365.

Log message is not clear when ConfigurationProvider failed to find
hadoop conf
Add Release Notes for version 0.6.0 (#346).
Merge remote-tracking branch 'private/issue/346-M7' into 0.6-develop
Merge remote-tracking branch 'private/issue/365' into 0.6-develop
Merge remote-tracking branch 'private/0.6-develop' into 0.6-hadoop2-develop