fix quotes causing dist errors

Author: Dottenpixel

ui/components/buttons/base/_index.scss

@@ -1,8 +1,7 @@
 // Copyright (c) 2015-present, salesforce.com, inc. All rights reserved
 // Licensed under BSD 3-Clause - see LICENSE.txt or git.io/sfdc-license
-
-@import "deprecate";
-@import "../mixins/index";
+@import 'deprecate';
+@import '../mixins/index';
 
 /**
  * @summary This neutralizes all the base styles making it look like a text link