Merge pull request #38 from BafS/upgrade-gulp-sass-v5-1

Upgrade gulp-sass to v5

Author: BafS

README.md

@@ -41,8 +41,8 @@ npm install gutenberg-css
 You can also use the unpkg service as a *CDN*.
 
 ```html
-<link rel="stylesheet" href="https://unpkg.com/gutenberg-css@0.6" media="print">
-<link rel="stylesheet" href="https://unpkg.com/gutenberg-css@0.6/dist/themes/oldstyle.min.css" media="print">
+<link rel="stylesheet" href="https://unpkg.com/gutenberg-css@0.7" media="print">
+<link rel="stylesheet" href="https://unpkg.com/gutenberg-css@0.7/dist/themes/oldstyle.min.css" media="print">
 ```