Added serde feature flags to tests

src/naive_bayes/bernoulli.rs

@@ -351,6 +351,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg(feature = "serde")]
     fn serde() {
         let x = DenseMatrix::<f64>::from_2d_array(&[
             &[1., 1., 0., 0., 0., 0.],

src/naive_bayes/categorical.rs

@@ -349,6 +349,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg(feature = "serde")]
     fn serde() {
         let x = DenseMatrix::<f64>::from_2d_array(&[
             &[3., 4., 0., 1.],

src/naive_bayes/gaussian.rs

@@ -281,6 +281,7 @@ mod tests {
     }
 
     #[test]
+    #[cfg(feature = "serde")]
     fn serde() {
         let x = DenseMatrix::<f64>::from_2d_array(&[
             &[-1., -1.],

src/naive_bayes/multinomial.rs

@@ -324,6 +324,7 @@ mod tests {
         ));
     }
     #[test]
+    #[cfg(feature = "serde")]
     fn serde() {
         let x = DenseMatrix::<f64>::from_2d_array(&[
             &[1., 1., 0., 0., 0., 0.],