Add min and max alias for amin and amax, to mimick numpy.
Add min and max alias for amin and amax, to mimick numpy.

benob/chainer,ysekky/chainer,ktnyt/chainer,hvy/chainer,chainer/chainer,ktnyt/chainer,sinhrks/chainer,okuta/chainer,wkentaro/chainer,cupy/cupy,hvy/chainer,okuta/chainer,AlpacaDB/chainer,niboshi/chainer,keisuke-umezawa/chainer,sinhrks/chainer,t-abe/chainer,chainer/chainer,delta2323/chainer,cupy/cupy,hvy/chainer,tkerola/chainer,muupan/chainer,rezoo/chainer,keisuke-umezawa/chainer,ktnyt/chainer,wkentaro/chainer,kashif/chainer,wkentaro/chainer,jnishi/chainer,kikusu/chainer,ronekko/chainer,t-abe/chainer,cemoody/chainer,cupy/cupy,keisuke-umezawa/chainer,kikusu/chainer,jnishi/chainer,hvy/chainer,benob/chainer,niboshi/chainer,kiyukuta/chainer,AlpacaDB/chainer,truongdq/chainer,niboshi/chainer,okuta/chainer,cupy/cupy,ktnyt/chainer,niboshi/chainer,jnishi/chainer,pfnet/chainer,chainer/chainer,anaruse/chainer,wkentaro/chainer,keisuke-umezawa/chainer,chainer/chainer,okuta/chainer,aonotas/chainer,jnishi/chainer,muupan/chainer,truongdq/chainer