NearestNeighbor.java failed to execute op hashcode

[LiuZheng-China]

Issue Description
when executing NearestNeighbor.java, which is in cifar directory of dl4j-examples, in line 105, when putting data into trainingMap, RuntimeException Op[hashcode] occured, failed to execute op hashcode .

input is double, output is float

Version Information
Please indicate relevant versions, including, if relevant:
dl4j-examples 1.0-beta5
windows x86_64
cpu,no cuda

[saudet]

/cc @AlexDBlack