Limit error API to a single enum

Author: huangsam

rustoku-cli/tests/cli_tests.rs

@@ -1,5 +1,5 @@
 use assert_cmd::prelude::*;
-use rustoku_lib::error::RustokuError;
+use rustoku_lib::RustokuError;
 use std::process::Command;
 
 /// Helper function to get the path to our compiled binary

rustoku-lib/src/lib.rs

@@ -10,7 +10,7 @@
 //! one-line representation for easy copying and pasting.
 
 pub mod core;
-pub mod error;
+mod error;
 mod format;
 
 pub use core::{Rustoku, generate_board};