Removed required prop and fixed component name.

src/components/layers/LayerListGroup.jsx

@@ -1,10 +1,9 @@
 import React from 'react'
 import Collapser from './Collapser'
 
-export default class LayerEditorGroup extends React.Component {
+export default class LayerListGroup extends React.Component {
   static propTypes = {
     title: React.PropTypes.string.isRequired,
-    children: React.PropTypes.element.isRequired,
     isActive: React.PropTypes.bool.isRequired,
     onActiveToggle: React.PropTypes.func.isRequired
   }