Travis has java 1.7 as default, so need to setup 1.8
Travis has java 1.7 as default, so need to setup 1.8

Signed-off-by: yukaReal <ec284419ba7e1427ecf8576c9ddf8275d6d3038b@gmail.com>

mibrahim/DataGenerator,leeny324/DataGenerator,yukaReal/DataGenerator,SamerAdra/DataGenerator,FINRAOS/DataGenerator,santiagos11/DataGenerator