Correct mistake made in #281830 for sprockets

Author: BookOfGreg

test/dummy_sprockets/app/assets/javascripts/components/TodoListWithConsoleLog.js.jsx

@@ -3,7 +3,7 @@ TodoListWithConsoleLog = createReactClass({
     console.log('got initial state');
     return({mounted: "nope"});
   },
-  componentDidMount: function() {
+  componentWillMount: function() {
     console.warn('mounted component');
     this.setState({mounted: 'yep'});
   },

test/dummy_sprockets/app/assets/javascripts/components/WithSetTimeout.js.jsx

@@ -1,5 +1,5 @@
 WithSetTimeout = createReactClass({
-  componentDidMount: function () {
+  componentWillMount: function () {
     setTimeout(function () {}, 1000)
     clearTimeout(0)
   },