Also replace root version to Python3

Philip Kahn

2018-05-04 3459c47bfa02d23d300df9a44ba3ec9c958850fe

 src/matrix.c

@@ -22,8 +22,8 @@
    for(i = 0; i < truth.rows; ++i){
        top_k(guess.vals[i], n, k, indexes);
        for(j = 0; j < k; ++j){
            int class = indexes[j];
            if(truth.vals[i][class]){
            int class_id = indexes[j];
            if(truth.vals[i][class_id]){
                ++correct;
                break;
            }