use Scratch3Registration instead of JoinModal in /join

src/views/join/join.jsx

@@ -1,6 +1,6 @@
 const React = require('react');
 const render = require('../../lib/render.jsx');
-const JoinModal = require('../../components/modal/join/modal.jsx');
+const Scratch3Registration = require('../../components/registration/scratch3-registration.jsx');
 const ErrorBoundary = require('../../components/errorboundary/errorboundary.jsx');
 // Require this even though we don't use it because, without it, webpack runs out of memory...
 const Page = require('../../components/page/www/page.jsx'); // eslint-disable-line no-unused-vars
@@ -20,7 +20,8 @@ const Register = () => (
             </a>
 
         </div>
-        <JoinModal
+        <Scratch3Registration
+            createProjectOnComplete
             isOpen
             key="scratch3registration"
             showCloseButton={false}