/**
 * Hint HTML
 */
'use strict';

const gulp     = require('gulp'),
      htmlhint = require('gulp-htmlhint'),
      notify   = require('gulp-notify');

module.exports = function(options) {

  return cb => {
    gulp.src('./*.html')
      .pipe(htmlhint({
        'attr-lowercase': ['viewBox']
      }))
      .pipe(htmlhint.reporter('htmlhint-stylish'))
      .pipe(htmlhint.failReporter({
        suppress: true 
      }))
      .on('error', notify.onError({
        title: 'HTML'
      }));

    cb();
  };

};
/**
 * Hint HTML
 */
'use strict';

const gulp     = require('gulp'),
      htmlhint = require('gulp-htmlhint'),
      notify   = require('gulp-notify');

module.exports = function(options) {

  return cb => {
    gulp.src('./*.html')
      .pipe(htmlhint())
      .pipe(htmlhint.reporter('htmlhint-stylish'))
      .pipe(htmlhint.failReporter({
        suppress: true 
      }))
      .on('error', notify.onError({
        title: 'HTML'
      }));

    cb();
  };

};
--- 
+++ 
@@ -11,7 +11,9 @@
 
   return cb => {
     gulp.src('./*.html')
-      .pipe(htmlhint())
+      .pipe(htmlhint({
+        'attr-lowercase': ['viewBox']
+      }))
       .pipe(htmlhint.reporter('htmlhint-stylish'))
       .pipe(htmlhint.failReporter({
         suppress: true 
Add the 'viewBox' attribute to htmlhint ignore list
