Fixes a bug that the parent project is missing from Maven repo (#511)
Fixes a bug that the parent project is missing from Maven repo (#511)


shimamoto/incubator-predictionio,marevol/incubator-predictionio,takezoe/incubator-predictionio,shimamoto/incubator-predictionio,marevol/incubator-predictionio,takezoe/incubator-predictionio,PredictionIO/PredictionIO,marevol/incubator-predictionio,marevol/incubator-predictionio,takezoe/incubator-predictionio,takezoe/incubator-predictionio,PredictionIO/PredictionIO,shimamoto/incubator-predictionio,PredictionIO/PredictionIO,shimamoto/incubator-predictionio