Update to use prop-types module in components.

src/components/layers/LayerSourceLayerBlock.jsx

@@ -1,4 +1,5 @@
 import React from 'react'
+import PropTypes from 'prop-types'
 
 import styleSpec from '@mapbox/mapbox-gl-style-spec'
 import InputBlock from '../inputs/InputBlock'
@@ -8,9 +9,9 @@ import AutocompleteInput from '../inputs/AutocompleteInput'
 
 class LayerSourceLayer extends React.Component {
   static propTypes = {
-    value: React.PropTypes.string,
-    onChange: React.PropTypes.func,
-    sourceLayerIds: React.PropTypes.array,
+    value: PropTypes.string,
+    onChange: PropTypes.func,
+    sourceLayerIds: PropTypes.array,
   }
 
   static defaultProps = {