Bump dependencies

scripts/grade-write_c.sh

@@ -4,8 +4,8 @@
 set -e
 
 # Run lints.
-cargo fmt --all -- --check # run `cargo fmt` to auto-correct format.
-cargo clippy
+cargo fmt --all -- --check # run `cargo fmt` to auto-correct the code. 
+cargo clippy               # run `cargo clippy --fix` to auto-correct the code.
 
 # Run tests.
 RUST_MIN_STACK=33554432 cargo test --release test_examples_write_c -- --nocapture