<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Live PI Charts</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="//fonts.googleapis.com/css?family=Open+Sans:400,700">
    <link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
    <!-- inject:css -->
    <!-- endinject -->
  </head>
  <body></body>
  <script src="http://d3js.org/d3.v3.min.js" charset="utf-8"></script>
  <script src="./assets/nvd3.js" type="text/javascript"></script>
  <script src="./main.js"></script>
</html>

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Live PI Charts</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="stylesheet" href="//fonts.googleapis.com/css?family=Open+Sans:400,700">
    <link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css">
    <!-- inject:css -->
    <!-- endinject -->
  </head>
  <body></body>
  <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.6/d3.min.js"></script>
  <script src="./assets/nvd3.js" type="text/javascript"></script>
  <script src="./main.js"></script>
</html>

Use Cloudflare as D3 cdn
Use Cloudflare as D3 cdn
