Fix negative test and also check NumPy consistency
Fix negative test and also check NumPy consistency

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