Update flatten workaround.

1 files changed, 1 insertions, 0 deletions

diff --git a/Cargo.toml b/Cargo.toml
index 4a643d7..51c5355 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -26,6 +26,7 @@ csv = "1.1"
 rand = "0.8"
 serde_derive = "1.0"
 serde_urlencoded = "0.7"
+serde_with = "1.10"
 
 [features]
 default = []