Move a few modules to util

src/main.rs

@@ -15,15 +15,13 @@ pub mod benchmark;
 pub mod command;
 pub mod error;
 pub mod export;
-pub mod min_max;
-pub mod number;
 pub mod options;
 pub mod outlier_detection;
 pub mod output;
 pub mod parameter;
 pub mod shell;
 pub mod timer;
-pub mod units;
+pub mod util;
 
 pub fn write_benchmark_comparison(results: &[BenchmarkResult]) {
     if results.len() < 2 {