remove shellwords crate

Cargo.toml

@@ -33,7 +33,6 @@ regex = "1.0"
 rustyline = "5.0.4"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
-shellwords = "1.0"
 siphasher = "0.3"
 syslog = "4.0"
 tokio = { version = "0.2.0-alpha.4" }