Fix negative nonces failing to deserialize

Negative message nonces caused deserialization errors, as serde would
not deserialize integers into strings.

To fix this, change `Message::nonce` into an `Option<Snowflake>` from an
`Option<String>`. This new `Snowflake` is a wrapper around an `i64`. Use
a new `I64Visitor` to deserialize i64s, u64s, and strs into the wanted
i64.

1 files changed, 4 insertions, 0 deletions

diff --git a/tests/test_deser.rs b/tests/test_deser.rs
index f4387bc..1024492 100644
--- a/tests/test_deser.rs
+++ b/tests/test_deser.rs
@@ -111,7 +111,11 @@ fn guild_update() {
 
 #[test]
 fn message_create() {
+    // standard
     p!(MessageCreateEvent, "message_create_1");
+
+    // negative nonce
+    p!(MessageCreateEvent, "message_create_2");
 }
 
 #[test]