Fix issue where numeric node values could trigger PropType warnings

Going back several builds, there were actually warnings to this effect being outputted to the console. Resolves #105.

Author: jakezatecky

src/js/CheckboxTree.js

@@ -5,17 +5,18 @@ import React from 'react';
 import nanoid from 'nanoid';
 
 import TreeNode from './TreeNode';
+import listShape from './listShape';
 import nodeShape from './nodeShape';
 
 class CheckboxTree extends React.Component {
     static propTypes = {
         nodes: PropTypes.arrayOf(nodeShape).isRequired,
 
-        checked: PropTypes.arrayOf(PropTypes.string),
+        checked: listShape,
         disabled: PropTypes.bool,
         expandDisabled: PropTypes.bool,
         expandOnClick: PropTypes.bool,
-        expanded: PropTypes.arrayOf(PropTypes.string),
+        expanded: listShape,
         name: PropTypes.string,
         nameAsArray: PropTypes.bool,
         nativeCheckboxes: PropTypes.bool,

src/js/TreeNode.js

@@ -15,7 +15,10 @@ class TreeNode extends React.Component {
         optimisticToggle: PropTypes.bool.isRequired,
         showNodeIcon: PropTypes.bool.isRequired,
         treeId: PropTypes.string.isRequired,
-        value: PropTypes.string.isRequired,
+        value: PropTypes.oneOfType([
+            PropTypes.string,
+            PropTypes.number,
+        ]).isRequired,
         onCheck: PropTypes.func.isRequired,
         onExpand: PropTypes.func.isRequired,
 

src/js/listShape.js

@@ -0,0 +1,8 @@
+import PropTypes from 'prop-types';
+
+const listShape = PropTypes.oneOfType([
+    PropTypes.arrayOf(PropTypes.string),
+    PropTypes.arrayOf(PropTypes.number),
+]);
+
+export default listShape;