message: Replaced String::serialize for serializer.serialize_str
diff: @@ -48,7 +48,7 @@ impl Serialize for Value {
  Value::Bool(b) => serializer.serialize_bool(b),
  Value::Date(ref date) => time::serde::rfc3339::serialize(&date.into_utc(), serializer),
  Value::Facet(ref facet) => facet.serialize(serializer),
  - Value::Bytes(ref bytes) => String::serialize(&base64::encode(bytes), serializer),
  + Value::Bytes(ref bytes) => serializer.serialize_str(&base64::encode(bytes)),
  Value::JsonObject(ref obj) => obj.serialize(serializer),
  }
  }
  