Run clang-tidy in parellel
Run clang-tidy in parellel

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