following flake8
following flake8

kiyukuta/chainer,chainer/chainer,ktnyt/chainer,ktnyt/chainer,ktnyt/chainer,kashif/chainer,ysekky/chainer,cupy/cupy,jnishi/chainer,okuta/chainer,niboshi/chainer,niboshi/chainer,okuta/chainer,wkentaro/chainer,okuta/chainer,niboshi/chainer,keisuke-umezawa/chainer,hvy/chainer,cupy/cupy,hvy/chainer,jnishi/chainer,keisuke-umezawa/chainer,niboshi/chainer,ktnyt/chainer,hvy/chainer,anaruse/chainer,rezoo/chainer,keisuke-umezawa/chainer,wkentaro/chainer,hvy/chainer,tkerola/chainer,ronekko/chainer,wkentaro/chainer,cupy/cupy,jnishi/chainer,jnishi/chainer,cupy/cupy,chainer/chainer,keisuke-umezawa/chainer,pfnet/chainer,wkentaro/chainer,delta2323/chainer,okuta/chainer,aonotas/chainer,chainer/chainer,chainer/chainer