add more missing role="form"-s

examples/jumbotron/index.html

@@ -40,7 +40,7 @@
           <a class="navbar-brand" href="#">Project name</a>
         </div>
         <div class="navbar-collapse collapse">
-          <form class="navbar-form navbar-right">
+          <form class="navbar-form navbar-right" role="form">
             <div class="form-group">
               <input type="text" placeholder="Email" class="form-control">
             </div>

examples/signin/index.html

@@ -30,7 +30,7 @@
 
     <div class="container">
 
-      <form class="form-signin">
+      <form class="form-signin" role="form">
         <h2 class="form-signin-heading">Please sign in</h2>
         <input type="text" class="form-control" placeholder="Email address" required autofocus>
         <input type="password" class="form-control" placeholder="Password" required>