Update uuid to 0.6 (#257)

Author: Dylan-DPC

Cargo.toml

@@ -26,7 +26,7 @@ tokio-core = "0.1.6"
 tokio-io = "0.1"
 tokio-tls = "0.1"
 url = "1.2"
-uuid = { version = "0.5", features = ["v4"] }
+uuid = { version = "0.6", features = ["v4"] }
 
 [dev-dependencies]
 env_logger = "0.5"