aggiunti css bootstrap

app/index.html

@@ -22,6 +22,7 @@
     <!-- endbower -->
     <!-- endbuild -->
     <!-- build:css(.tmp) styles/main.css -->
+<link rel="stylesheet" href="/bower_components/bootstrap/dist/css/bootstrap.css">
     <link rel="stylesheet" href="styles/main.css">
     <!-- endbuild -->