other: add fmt to husky hook (#731)

Just adds a cargo fmt check to the husky pre-push check.

.cargo-husky/hooks/pre-push

@@ -4,6 +4,9 @@ set -e
 
 echo "Running pre-push hook:"
 
+echo "Checking fmt"
+cargo fmt --all -- --check
+
 echo "Executing: cargo clippy --all-targets --workspace -- -D warnings"
 cargo clippy --all-targets --workspace -- -D warnings