XD-466 Add Json support to Tuple
XD-466 - renamed JSon to Json and minor changes per PR review comments
XD-466 - revert build.gradle
XD-476 correct the AbstractRedisRepository to delete the correct key based on the repoPrefix
XD-388 Add webhdfs dependencies to classpath

Add jar files needed to use webhdfs for hdfs sink
Merge branch 'XD-476' of github.com:datianshi/spring-xd into datianshi-XD-476
Merge branch 'XD-466'