set errorboundary name tag everywhere ErrorBoundary is used

src/components/page/www/page.jsx

@@ -10,7 +10,7 @@ const Page = ({
     children,
     className
 }) => (
-    <ErrorBoundary>
+    <ErrorBoundary name="page">
         <div className={classNames('page', className)}>
             <div
                 className={classNames({

src/views/join/join.jsx

@@ -5,9 +5,12 @@ 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
 
+const initSentry = require('../../lib/sentry.js');
+initSentry();
+
 require('./join.scss');
 const Register = () => (
-    <ErrorBoundary>
+    <ErrorBoundary name="join">
         <div className="join">
             <a
                 aria-label="Scratch"

src/views/preview/embed-view.jsx

@@ -35,7 +35,7 @@ class EmbedView extends React.Component {
     render () {
         if (this.props.projectNotAvailable || this.state.invalidProject) {
             return (
-                <ErrorBoundary>
+                <ErrorBoundary name="embed">
                     <div className="preview">
                         <NotAvailable />
                     </div>

src/views/preview/embed.jsx

@@ -26,5 +26,8 @@ if (isSupportedBrowser()) {
         EmbedView.guiMiddleware
     );
 } else {
-    render(<ErrorBoundary><UnsupportedBrowser /></ErrorBoundary>, document.getElementById('app'));
+    render(
+        <ErrorBoundary name="unsupportedbrowser"><UnsupportedBrowser /></ErrorBoundary>,
+        document.getElementById('app')
+    );
 }