Don't use parallel Maven build on Travis
Don't use parallel Maven build on Travis

zxing/zxing,daverix/zxing,shixingxing/zxing,daverix/zxing,daverix/zxing,daverix/zxing,zxing/zxing,l-dobrev/zxing,tanelihuuskonen/zxing,tanelihuuskonen/zxing,shixingxing/zxing,l-dobrev/zxing,daverix/zxing