refactor: optimize import and last_tweet_id var

src/twitter.rs

@@ -1,12 +1,8 @@
-// auto-imports
 use crate::ScootalooError;
 use crate::config::TwitterConfig;
 use crate::util::cache_media;
 
-// std
 use std::error::Error;
-
-// egg-mode
 use egg_mode::{
     Token,
     KeyPair,