build: Bump stylelint and make pass

grunt-stylelint              0.6.0  →   0.7.0
 stylelint-config-wikimedia   0.3.0  →   0.4.1

Change-Id: Id87b8df04d415e1f1058a4042a31408236402037

resources/css/ext.uls.pt.less

@@ -26,11 +26,13 @@
 /* Opera for some inexplicable reason confuses right and left padding with */
 /* RTL text direction here (bug T47142). x:-o-prefocus won't match anything, */
 /* but will make other browsers ignore this rule. */
+/* stylelint-disable selector-type-no-unknown */
 x:-o-prefocus,
 body.rtl li#pt-uls {
 	/* @noflip */
 	direction: ltr;
 }
+/* stylelint-enable selector-type-no-unknown */
 
 /* Don't show it to users who disabled JS */
 .client-nojs #pt-uls {