Bump strum from 0.20.0 to 0.21.0

Bumps [strum](https://github.com/Peternator7/strum) from 0.20.0 to 0.21.0.
- [Release notes](https://github.com/Peternator7/strum/releases)
- [Changelog](https://github.com/Peternator7/strum/blob/master/CHANGELOG.md)
- [Commits](https://github.com/Peternator7/strum/commits)

Signed-off-by: dependabot[bot] <support@github.com>

Cargo.lock

@@ -3838,18 +3838,18 @@ dependencies = [
 
 [[package]]
 name = "strum"
-version = "0.20.0"
+version = "0.21.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7318c509b5ba57f18533982607f24070a55d353e90d4cae30c467cdb2ad5ac5c"
+checksum = "aaf86bbcfd1fa9670b7a129f64fc0c9fcbbfe4f1bc4210e9e98fe71ffc12cde2"
 dependencies = [
  "strum_macros",
 ]
 
 [[package]]
 name = "strum_macros"
-version = "0.20.1"
+version = "0.21.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ee8bc6b87a5112aeeab1f4a9f7ab634fe6cbefc4850006df31267f4cfb9e3149"
+checksum = "cb076d8b589fde927ec90d05920d610554ca3a4d9dddb177481cadd071a19c2e"
 dependencies = [
  "heck",
  "proc-macro2 1.0.24",

swap/Cargo.toml

@@ -49,7 +49,7 @@ sha2 = "0.9"
 sigma_fun = { git = "https://github.com/LLFourn/secp256kfun", default-features = false, features = [ "ed25519", "serde" ] }
 sled = "0.34"
 structopt = "0.3"
-strum = { version = "0.20", features = [ "derive" ] }
+strum = { version = "0.21", features = [ "derive" ] }
 thiserror = "1"
 time = "0.2"
 tokio = { version = "1", features = [ "rt-multi-thread", "time", "macros", "sync", "process", "fs", "net" ] }