Cubic-Spline: Clippy amendments

Author: yfnaji

crates/RustQuant_math/src/interpolation/cubic_spline.rs

@@ -187,7 +187,7 @@ where
     fn fit(&mut self) -> Result<(), RustQuantError> {
 
         self.time_steps = self.xs.windows(2)
-            .map(|x| (x[1] - x[0]))
+            .map(|x| x[1] - x[0])
             .collect();
 
         let mut rhs: Vec<ValueType> = self.xs.iter().zip(self.ys.iter())

crates/RustQuant_math/src/interpolation/mod.rs

@@ -7,7 +7,7 @@
 //      - LICENSE-MIT.md
 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-use std::{i8, ops::{Add, AddAssign, Div, Mul, MulAssign, Neg, Sub}};
+use std::ops::{Add, AddAssign, Div, Mul, MulAssign, Neg, Sub};
 use rust_decimal::prelude::*;
 use RustQuant_error::RustQuantError;