Fix validation errors.

[skip sauce]

docs/_includes/footer.html

@@ -1,4 +1,4 @@
-<footer class="bd-footer text-muted" role="contentinfo">
+<footer class="bd-footer text-muted">
   <div class="container">
     <ul class="bd-footer-links">
       <li><a href="{{ site.repo }}">GitHub</a></li>

docs/_includes/nav-home.html

@@ -1,4 +1,4 @@
-<header class="navbar navbar-light navbar-static-top bd-navbar" role="banner">
+<header class="navbar navbar-light navbar-static-top bd-navbar">
   <div class="container">
     {% comment %}
     <nav class="nav navbar-nav pull-xs-right">

docs/components/scrollspy.md

@@ -14,7 +14,7 @@ group: components
 The ScrollSpy plugin is for automatically updating nav targets based on scroll position. Scroll the area below the navbar and watch the active class change. The dropdown sub items will be highlighted as well.
 
 <div class="bd-example">
-  <nav id="navbar-example2" class="navbar navbar-default" role="navigation">
+  <nav id="navbar-example2" class="navbar navbar-default">
     <h3 class="navbar-brand">Project Name</h3>
     <ul class="nav nav-pills">
       <li class="nav-item"><a class="nav-link" href="#fat">@fat</a></li>

docs/index.html

@@ -3,7 +3,7 @@ layout: home
 title: Bootstrap · The world's most popular mobile-first and responsive front-end framework.
 ---
 
-<main class="bd-masthead" id="content" role="main">
+<main class="bd-masthead" id="content">
   <div class="container">
     <span class="bd-booticon outline">B</span>
     <p class="lead">Bootstrap is the most popular HTML, CSS, and JS framework in the world for building responsive, mobile-first projects on the web.</p>

js/tests/visual/dropdown.html

@@ -15,7 +15,7 @@
     <h1>Dropdown <small>Bootstrap Visual Test</small></h1>
   </div>
 
-  <nav id="navbar-example" class="navbar navbar-light bg-faded" role="navigation">
+  <nav id="navbar-example" class="navbar navbar-light bg-faded">
     <button class="navbar-toggler hidden-sm-up" type="button" data-toggle="collapse" data-target="#exCollapsingNavbar2">
       &#9776;
     </button>

js/tests/visual/scrollspy.html

@@ -14,7 +14,7 @@
 
 <div class="container">
 
-  <nav class="navbar navbar-dark navbar-fixed-top bg-inverse" role="navigation">
+  <nav class="navbar navbar-dark navbar-fixed-top bg-inverse">
     <div class="js-navbar-scrollspy">
       <ul class="nav navbar-nav">
         <li class="nav-item"><a class="nav-link active" href="#fat">@fat</a></li>