title: Split output of a layer in keras
body: <p>Say, I have a layer with output dims (4, x, y). I want to split this into 4 separate (1, x, y) tensors, which I can use as input for 4 other layers.</p>
  
  <p>What I'm essentially looking for is the opposite of the Merge layer. I know that there's no split layer in keras, but is there a simple way to do this in keras?</p>