Use prop-types package instead of React.PropTypes.

Author: leMaik

src/McText.js

@@ -1,4 +1,5 @@
-import React, { PropTypes } from 'react'
+import React from 'react'
+import PropTypes from 'prop-types'
 import defaultColormap from './defaultColormap'
 import convertTextToJson from './textToJson'
 import TextComponent from './TextComponent'

src/ObfuscatedText.js

@@ -1,4 +1,5 @@
-import React, { Component, PropTypes } from 'react'
+import React, { Component } from 'react'
+import PropTypes from 'prop-types'
 
 export default class ObfuscatedText extends Component {
   generateText () {

src/TextComponent.js

@@ -1,4 +1,5 @@
-import React, { PropTypes } from 'react'
+import React from 'react'
+import PropTypes from 'prop-types'
 import ObfuscatedText from './ObfuscatedText'
 import { isString } from './util'