Add clippy config to the root crate

Author: aldanor

src/lib.rs

@@ -1,3 +1,16 @@
+#![warn(clippy::all, clippy::pedantic, clippy::nursery, clippy::cargo)]
+#![allow(
+    clippy::cast_possible_truncation,
+    clippy::cast_possible_wrap,
+    clippy::cast_sign_loss,
+    clippy::cast_lossless,
+    clippy::cast_precision_loss,
+    clippy::missing_const_for_fn,
+    clippy::use_self,
+    clippy::module_name_repetitions,
+    clippy::cargo_common_metadata
+)]
+
 use std::error::Error as StdError;
 use std::fmt::{self, Display};