Change unused dependency to dev_dependency (cloudevents#103)

Signed-off-by: tottoto <[email protected]>

Author: tottoto

cloudevents-sdk-actix-web/Cargo.toml

@@ -15,13 +15,13 @@ categories = ["web-programming", "encoding", "web-programming::http-server"]
 [dependencies]
 cloudevents-sdk = { version = "0.3.0", path = ".." }
 actix-web = { version = "^3", default-features = false }
-actix-rt = "^1"
 async-trait = "^0.1.33"
 lazy_static = "1.4.0"
 bytes = "^0.5"
 futures = "^0.3"
 
 [dev-dependencies]
+actix-rt = "^1"
 url = { version = "^2.1", features = ["serde"] }
 serde_json = "^1.0"
 chrono = { version = "^0.4", features = ["serde"] }