Remove redundant dtype assertions in Python tests
Remove redundant dtype assertions in Python tests

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