Add registration component to `JOIN SCRATCH`

fixes #122

src/components/intro/intro.jsx

@@ -5,6 +5,7 @@ var FormattedMessage = ReactIntl.FormattedMessage;
 var FormattedHTMLMessage = ReactIntl.FormattedHTMLMessage;
 
 var Modal = require('../modal/modal.jsx');
+var Registration = require('../registration/registration.jsx');
 
 require('./intro.scss');
 
@@ -31,6 +32,17 @@ var Intro = React.createClass({
     closeVideo: function () {
         this.setState({videoOpen: false});
     },
+    handleJoinClick: function (e) {
+        e.preventDefault();
+        this.setState({'registrationOpen': true});
+    },
+    closeRegistration: function () {
+        this.setState({'registrationOpen': false});
+    },
+    completeRegistration: function () {
+        window.refreshSession();
+        this.closeRegistration();
+    },
     render: function () {
         var frameSettings = {
             width: 570,
@@ -77,7 +89,7 @@ var Intro = React.createClass({
                                     defaultMessage='SEE EXAMPLES' />
                             </div>
                         </a>
-                        <a className="sprite sprite-3" href="#">
+                        <a className="sprite sprite-3" href="#" onClick={this.handleJoinClick}>
                             <img
                                 className="costume costume-1"
                                 src="//cdn.scratch.mit.edu/scratchr2/static/images/gobo-a.png" />
@@ -92,6 +104,10 @@ var Intro = React.createClass({
                             </div>
                             <div className="text subtext">( it&rsquo;s free )</div>
                         </a>
+                        <Registration key="registration"
+                                      isOpen={this.state.registrationOpen}
+                                      onRequestClose={this.closeRegistration}
+                                      onRegistrationDone={this.completeRegistration} />
                     </div>
                     <div className="description">
                         A creative learning community with