SVC crashes on a test dataset with non default C

[montanalow]

This test passes with a default C parameter of 1.0, but crashes on 0.0 or 10.0 at different places. It also passes with non default C values on trivial datasets, so it's an issue only exposed at larger scales.

[Mec-iS]

this should be in a issue if we follow with the strategy proposed by #154 (comment)

EDIT: I put here the failing test

   #[cfg_attr(target_arch = "wasm32", wasm_bindgen_test::wasm_bindgen_test)]
    #[test]
    fn svc_fit_predict_c() {
        let breast_cancer = crate::dataset::breast_cancer::load_dataset();
        let y = breast_cancer.target;
        let x = DenseMatrix::from_array(
            breast_cancer.num_samples,
            breast_cancer.num_features,
            &breast_cancer.data,
        );

        let y_hat = SVC::fit(
            &x,
            &y,
            SVCParameters::default()
                .with_c(10.0)
                .with_kernel(Kernels::linear()),
        )
        .and_then(|lr| lr.predict(&x))
        .unwrap();

        assert!(accuracy(&y_hat, &y) >= 0.9);
    }