🚨Fix Rubocop lint errors

app/models/inbox_member.rb

@@ -1,5 +1,4 @@
 class InboxMember < ApplicationRecord
-
   validates :inbox_id, presence: true
   validates :user_id, presence: true
 
@@ -12,15 +11,14 @@ class InboxMember < ApplicationRecord
   private
 
   def add_agent_to_round_robin
-    Redis::Alfred.lpush(round_robin_key, self.user_id)
+    Redis::Alfred.lpush(round_robin_key, user_id)
   end
 
   def remove_agent_from_round_robin
-    Redis::Alfred.lrem(round_robin_key, self.user_id)
+    Redis::Alfred.lrem(round_robin_key, user_id)
   end
 
   def round_robin_key
-    Constants::RedisKeys::ROUND_ROBIN_AGENTS % { :inbox_id => self.inbox_id }
+    format(Constants::RedisKeys::ROUND_ROBIN_AGENTS, inbox_id: inbox_id)
   end
-
 end