added a 404 page

react/components/FourOhFourPage/index.js

@@ -0,0 +1,18 @@
+import React from 'react';
+import NavBar from 'containers/NavBar';
+
+class FourOhForPage extends React.Component {
+  render () {
+    return (
+      <div>
+        <NavBar/>
+        <div className="row row--padded">
+            <h2>404</h2>
+            <p>That page does not exist</p>
+        </div>
+      </div>
+    );
+  }
+};
+
+export default FourOhForPage;

react/root.js

@@ -7,6 +7,7 @@ import PublishPage from 'components/PublishPage';
 import AboutPage from 'components/AboutPage';
 import LoginPage from 'containers/LoginPage';
 import ShowPage from 'containers/ShowPage';
+import FourOhFourPage from 'components/FourOhFourPage';
 
 const Root = ({ store }) => (
   <Provider store={store}>
@@ -16,7 +17,8 @@ const Root = ({ store }) => (
         <Route exact path="/about" component={AboutPage} />
         <Route exact path="/login" component={LoginPage} />
         <Route exact path="/:identifier/:claim" component={ShowPage} />
-        <Route exact path="/:claim/" component={ShowPage} />
+        <Route exact path="/:claim" component={ShowPage} />
+        <Route component={FourOhFourPage} />
       </Switch>
     </BrowserRouter>
   </Provider>