style: Disable camelcase rule for GObject properties

For GObject properties, we follow the convention of all-lowercase,
dash-separated names. Those translate to underscores in getters/setters,
so exempt them from the newly added "camelcase" rule.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/627

js/ui/altTab.js

@@ -662,6 +662,7 @@ class AppIcon extends St.BoxLayout {
         this.add(this.label, { x_fill: false });
     }
 
+    // eslint-disable-next-line camelcase
     set_size(size) {
         this.icon = this.app.create_icon_texture(size);
         this._iconBin.child = this.icon;