Move a few modules to util

src/output/format.rs

@@ -1,4 +1,4 @@
-use crate::units::{Second, Unit};
+use crate::util::units::{Second, Unit};
 
 /// Format the given duration as a string. The output-unit can be enforced by setting `unit` to
 /// `Some(target_unit)`. If `unit` is `None`, it will be determined automatically.

src/output/warnings.rs

@@ -2,7 +2,7 @@ use std::fmt;
 
 use crate::benchmark::MIN_EXECUTION_TIME;
 use crate::output::format::format_duration;
-use crate::units::Second;
+use crate::util::units::Second;
 
 /// A list of all possible warnings
 pub enum Warnings {