Fix new warnings after rustup update

Author: morenol

src/dataset/generator.rs

@@ -49,7 +49,7 @@ pub fn make_blobs(
 
 /// Make a large circle containing a smaller circle in 2d.
 pub fn make_circles(num_samples: usize, factor: f32, noise: f32) -> Dataset<f32, f32> {
-    if factor >= 1.0 || factor < 0.0 {
+    if !(0.0..1.0).contains(&factor) {
         panic!("'factor' has to be between 0 and 1.");
     }
 

src/linear/logistic_regression.rs

@@ -328,8 +328,10 @@ impl<T: RealNumber, M: Matrix<T>> LogisticRegression<T, M> {
 
         let df = |g: &mut M, w: &M| objective.df(g, w);
 
-        let mut ls: Backtracking<T> = Default::default();
-        ls.order = FunctionOrder::THIRD;
+        let ls: Backtracking<T> = Backtracking {
+            order: FunctionOrder::THIRD,
+            ..Default::default()
+        };
         let optimizer: LBFGS<T> = Default::default();
 
         optimizer.optimize(&f, &df, &x0, &ls)

src/model_selection/mod.rs

@@ -110,7 +110,7 @@ pub struct KFold {
 impl Default for KFold {
     fn default() -> KFold {
         KFold {
-            n_splits: 3 as usize,
+            n_splits: 3_usize,
             shuffle: true,
         }
     }