ref: remove comment about test module

Author: LeoPatOZ

tests/mod.rs

@@ -1,6 +1,3 @@
-// This test module triggers the `test-utils` feature when running
-// `cargo test`. Without it, you'd need to manually specify `--features test-utils`
-// every time.
 mod common;
 mod historic_mode;
 mod historic_to_live;