FIX: Skip trigger match should be case insensitive.

https://meta.discourse.org/t/discobot-not-skipping-tutorial/68498

plugins/discourse-narrative-bot/lib/discourse_narrative_bot/track_selector.rb

@@ -217,9 +217,7 @@ module DiscourseNarrativeBot
     def skip_track?
       if @is_pm_to_bot
         post_raw = @post.raw
-
-        post_raw.match(/^@#{self.discobot_user.username} #{self.class.skip_trigger}/i) ||
-          post_raw.strip == self.class.skip_trigger
+        post_raw.match(/((^@#{self.discobot_user.username} #{self.class.skip_trigger})|(^#{self.class.skip_trigger}$))/i)
       else
         false
       end