edition: run 'cargo fix --edition --edition-idioms --all'

crates/searcher/src/lib.rs

@@ -99,16 +99,8 @@ searches stdin.
 
 #![deny(missing_docs)]
 
-extern crate bstr;
-extern crate bytecount;
-extern crate encoding_rs;
-extern crate encoding_rs_io;
-extern crate grep_matcher;
 #[macro_use]
 extern crate log;
-extern crate memmap;
-#[cfg(test)]
-extern crate regex;
 
 pub use crate::lines::{LineIter, LineStep};
 pub use crate::searcher::{