Fix to use get_trigger instead of IntervalTrigger constructor.
Fix to use get_trigger instead of IntervalTrigger constructor.

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