Fix PropTypes in model-collapse component

Author: owenconti

src/core/components/model-collapse.jsx

@@ -1,4 +1,5 @@
-import React, { Component, PropTypes } from "react"
+import React, { Component } from "react"
+import PropTypes from "prop-types"
 
 export default class ModelCollapse extends Component {
   static propTypes = {