fix test

Author: isabelatkinson

src/tests/modules/bson.rs

@@ -18,9 +18,8 @@ use crate::{
     Timestamp,
 };
 
-use serde_json::Value;
-
 #[test]
+#[cfg(feature = "serde_json-1")]
 fn to_json() {
     let _guard = LOCK.run_concurrently();
     let mut doc = Document::new();
@@ -31,7 +30,7 @@ fn to_json() {
     doc.insert("first", Bson::Int32(1));
     doc.insert("second", Bson::String("foo".to_owned()));
     doc.insert("alphanumeric", Bson::String("bar".to_owned()));
-    let data: Value = Bson::Document(doc).into();
+    let data: serde_json::Value = Bson::Document(doc).into();
 
     assert!(data.is_object());
     let obj = data.as_object().unwrap();