Reduce roboto imports

app/styles/app-theme.html

@@ -1,3 +1,4 @@
+<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:400,300,500,700">
 <link rel="import" href="../bower_components/polymer/polymer.html">
 <style is="custom-style">
 :root {

gulpfile.js

@@ -192,6 +192,7 @@ gulp.task('vulcanize', function() {
     return gulp.src('app/elements/elements.html')
         .pipe($.vulcanize({
             stripComments: true,
+            stripExclude:['app/bower_components/font-roboto/roboto.html'],
             inlineCss: true,
             inlineScripts: true
         }))