Clean up imports from the rmp-serde example.

Signed-off-by: Aalekh Patel <[email protected]>

heed/examples/rmp-serde.rs

@@ -2,9 +2,7 @@ use std::error::Error;
 use std::fs;
 use std::path::Path;
 
-use heed::bytemuck::{Pod, Zeroable};
-use heed::byteorder::BE;
-use heed::types::*;
+use heed::types::{SerdeRmp, Str};
 use heed::{Database, EnvOpenOptions};
 use serde::{Deserialize, Serialize};