Make 2020 compile again

2020/src/bin/day03.rs

@@ -1,4 +1,3 @@
-#![feature(iter_map_while)]
 #![feature(test)]
 #![allow(clippy::ptr_arg)]
 extern crate test;

2020/src/bin/day17.rs

@@ -1,5 +1,5 @@
 #![allow(incomplete_features)]
-#![feature(test, const_generics, const_evaluatable_checked)]
+#![feature(test, generic_const_exprs)]
 extern crate test;
 use aoc2020::{
     common::*, grid::{self, cell::Cell, *}

2020/src/lib.rs

@@ -1,5 +1,5 @@
 #![allow(incomplete_features)]
-#![feature(const_generics, const_evaluatable_checked, test)]
+#![feature(generic_const_exprs, test)]
 pub mod common;
 pub mod grid;
 pub mod teststuff;