function attribute(morph, env, scope, name, value) {
  value = env.hooks.getValue(value);

  if (morph.lastValue !== value) {
    morph.setContent(value);
  }

  morph.lastValue = value;
}
Host hook: attribute

  @param {RenderNode} renderNode
  @param {Environment} env
  @param {String} name
  @param {any} value

  Corresponds to:

  ```hbs
  <div foo={{bar}}></div>
  ```

  This hook is responsible for updating a render node
  that represents an element's attribute with a value.

  It receives the name of the attribute as well as an
  already-resolved value, and should update the render
  node with the value if appropriate.