Update updater.py using six.itervalues()
Update updater.py using six.itervalues()

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