Use PropTypes from prop-types package

package.json

@@ -37,6 +37,7 @@
     "eslint-config-gitbook": "^1.4.0",
     "gh-pages": "^0.12.0",
     "http-server": "^0.9.0",
+    "prop-types": "^15.6.0",
     "react": "^15.4.1",
     "react-dom": "^15.4.1"
   },

src/context.js

@@ -1,5 +1,6 @@
 /* global MathJax */
 const React = require('react');
+const PropTypes = require('prop-types');
 const loadScript = require('load-script');
 
 const DEFAULT_SCRIPT =
@@ -19,16 +20,16 @@ const DEFAULT_OPTIONS = {
  */
 const MathJaxContext = React.createClass({
     propTypes: {
-        children: React.PropTypes.node.isRequired,
-        script:   React.PropTypes.oneOfType([
-            React.PropTypes.string,
-            React.PropTypes.oneOf([false])
+        children: PropTypes.node.isRequired,
+        script:   PropTypes.oneOfType([
+            PropTypes.string,
+            PropTypes.oneOf([false])
         ]),
-        options:  React.PropTypes.object
+        options:  PropTypes.object
     },
 
     childContextTypes: {
-        MathJax: React.PropTypes.object
+        MathJax: PropTypes.object
     },
 
     getDefaultProps() {

src/node.js

@@ -1,4 +1,5 @@
 const React = require('react');
+const PropTypes = require('prop-types');
 const process = require('./process');
 
 /**
@@ -7,13 +8,13 @@ const process = require('./process');
  */
 const MathJaxNode = React.createClass({
     propTypes: {
-        inline:   React.PropTypes.bool,
-        children: React.PropTypes.node.isRequired,
-        onRender: React.PropTypes.func
+        inline:   PropTypes.bool,
+        children: PropTypes.node.isRequired,
+        onRender: PropTypes.func
     },
 
     contextTypes: {
-        MathJax: React.PropTypes.object
+        MathJax: PropTypes.object
     },
 
     getDefaultProps() {