message: Add a bit of debugging to incorrect components in the Skinner
diff: @@ -58,7 +58,7 @@ class Skinner {
  // components have to be functions.
  const validType = typeof comp === 'function';
  if (!validType) {
  - throw new Error(`Not a valid component: ${name}.`);
  + throw new Error(`Not a valid component: ${name} (type = ${typeof(comp)}).`);
  }
  return comp;
  }
  