filter warnings raised in NumPy 1.15
filter warnings raised in NumPy 1.15

jnishi/chainer,tkerola/chainer,pfnet/chainer,niboshi/chainer,hvy/chainer,keisuke-umezawa/chainer,chainer/chainer,ktnyt/chainer,jnishi/chainer,ktnyt/chainer,ktnyt/chainer,chainer/chainer,keisuke-umezawa/chainer,hvy/chainer,wkentaro/chainer,wkentaro/chainer,niboshi/chainer,okuta/chainer,ktnyt/chainer,jnishi/chainer,chainer/chainer,chainer/chainer,niboshi/chainer,jnishi/chainer,okuta/chainer,hvy/chainer,wkentaro/chainer,okuta/chainer,keisuke-umezawa/chainer,hvy/chainer,okuta/chainer,wkentaro/chainer,niboshi/chainer,keisuke-umezawa/chainer