Copy euph-api-related parts from cove

Also includes the required dependencies and some minor changes to the
module structure, as well as all the clippy and rustc warnings.

src/lib.rs

@@ -1,14 +1,22 @@
-pub fn add(left: usize, right: usize) -> usize {
-    left + right
-}
+#![deny(unsafe_code)]
+// Rustc lint groups
+#![warn(future_incompatible)]
+#![warn(rust_2018_idioms)]
+// Rustc lints
+#![warn(noop_method_call)]
+#![warn(single_use_lifetimes)]
+#![warn(trivial_numeric_casts)]
+#![warn(unused_crate_dependencies)]
+#![warn(unused_extern_crates)]
+#![warn(unused_import_braces)]
+#![warn(unused_lifetimes)]
+#![warn(unused_qualifications)]
+// Clippy lints
+#![warn(clippy::use_self)]
 
-#[cfg(test)]
-mod tests {
-    use super::*;
+pub mod api;
+pub mod conn;
+mod huehash;
+pub mod replies;
 
-    #[test]
-    fn it_works() {
-        let result = add(2, 2);
-        assert_eq!(result, 4);
-    }
-}
+pub use huehash::nick_hue;