Run cargo clippy --fix (#250)

* Run `cargo clippy --fix`
* Run `cargo clippy --all-features --fix`
* Fix other clippy warnings
* cargo fmt

Co-authored-by: Luis Moreno <morenol@users.noreply.github.com>

src/optimization/first_order/gradient_descent.rs

@@ -113,12 +113,13 @@ mod tests {
             g[1] = 200. * (x[1] - x[0].powf(2.));
         };
 
-        let mut ls: Backtracking<f64> = Default::default();
-        ls.order = FunctionOrder::THIRD;
+        let ls: Backtracking<f64> = Backtracking::<f64> {
+            order: FunctionOrder::THIRD,
+            ..Default::default()
+        };
         let optimizer: GradientDescent = Default::default();
 
         let result = optimizer.optimize(&f, &df, &x0, &ls);
-        println!("{:?}", result);
 
         assert!((result.f_x - 0.0).abs() < 1e-5);
         assert!((result.x[0] - 1.0).abs() < 1e-2);

src/optimization/first_order/lbfgs.rs

@@ -196,9 +196,9 @@ impl LBFGS {
     }
 
     ///
-    fn update_hessian<'a, T: FloatNumber, X: Array1<T>>(
+    fn update_hessian<T: FloatNumber, X: Array1<T>>(
         &self,
-        _: &'a DF<'_, X>,
+        _: &DF<'_, X>,
         state: &mut LBFGSState<T, X>,
     ) {
         state.dg = state.x_df.sub(&state.x_df_prev);
@@ -291,8 +291,10 @@ mod tests {
             g[0] = -2. * (1. - x[0]) - 400. * (x[1] - x[0].powf(2.)) * x[0];
             g[1] = 200. * (x[1] - x[0].powf(2.));
         };
-        let mut ls: Backtracking<f64> = Default::default();
-        ls.order = FunctionOrder::THIRD;
+        let ls: Backtracking<f64> = Backtracking::<f64> {
+            order: FunctionOrder::THIRD,
+            ..Default::default()
+        };
         let optimizer: LBFGS = Default::default();
 
         let result = optimizer.optimize(&f, &df, &x0, &ls);