tools: add warp as a dependency

tools/Cargo.toml

@@ -11,3 +11,5 @@ license = "MIT"
 anyhow = "1.0"
 rust-fsm = "0.3.0"
 serde = { version = "1.0", features = ["derive"] }
+tokio = { version = "0.2", features = ["macros"] }
+warp = "0.2"

tools/src/letters.rs

@@ -3,7 +3,7 @@ use anyhow::{anyhow, Result};
 
 fn letter2ipa(l: &String) -> Result<String> {
     let l = l.as_str();
-    // /d f g h j k l m n p q s t w ʃ ʒ ʔ ʙ̥/
+    // /d f g h j k l m n p q r s t w ʃ ʒ ʔ ʙ̥/
     // /a ɛ i o u/
     match l {
         "a" => Ok("a".into()),