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

@@ -1906,7 +1906,7 @@ dependencies = [
  "serde",
  "serde_cbor",
  "serde_json",
- "strum 0.20.0",
+ "strum 0.21.0",
  "strum_macros 0.20.1",
  "tokio 1.6.1",
  "tokio-stream",
@@ -3218,9 +3218,9 @@ checksum = "4ca6e4730f517e041e547ffe23d29daab8de6b73af4b6ae2a002108169f5e7da"
 
 [[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"
 
 [[package]]
 name = "strum_macros"

Cargo.toml

@@ -42,7 +42,7 @@ rand = "0.8"
 webbrowser = "0.5"
 clipboard = { version = "0.5", optional = true }
 url = "2.2"
-strum = "0.20.0"
+strum = "0.21.0"
 strum_macros = "0.20.1"
 regex = "1"
 ioctl-rs = { version = "0.2", optional = true }