Add yaml-rust

Cargo.lock

@@ -76,6 +76,7 @@ dependencies = [
  "clap",
  "serde",
  "toml",
+ "yaml-rust",
 ]
 
 [[package]]

Cargo.toml

@@ -9,4 +9,5 @@ edition = "2018"
 [dependencies]
 toml = "0.5.6"
 serde = "1.0.116"
-clap = {version = "2.33.3", features = ["yaml"]}
+clap = {version = "2.33.3", features = ["yaml"]}
+yaml-rust = "0.3.5"