Fix updated clippy grumbles (#733)

* Revert "Pin Rust Nightly to 2020-12-17 (#652)"

This reverts commit e54e6f7e3d34c28d698e637f9099162b3c1917e9.

* fix clippy

* clippy again

* more clippy in test code

* and new cargo fmt

* another try

bridges/bin/rialto/runtime/src/lib.rs

@@ -23,6 +23,8 @@
 #![allow(clippy::large_enum_variant)]
 // Runtime-generated DecodeLimit::decode_all_With_depth_limit
 #![allow(clippy::unnecessary_mut_passed)]
+// From construct_runtime macro
+#![allow(clippy::from_over_into)]
 
 // Make the WASM binary available.
 #[cfg(feature = "std")]