Migrate to structured logging

src/data_provider/card_stats.rs

@@ -1,6 +1,7 @@
 use crate::lang::{CardStatistics, DeckSettings};
 use rusqlite::{Connection, params};
 use std::time::Instant;
+use log::info;
 
 pub fn load_stats_of_deck(set: &DeckSettings, connection: &Connection) -> Vec<CardStatistics> {
     let mut stmt = connection
@@ -58,7 +59,7 @@ pub fn add_stat_list(stats: &mut [CardStatistics], connection: &mut Connection)
         stats[index].id = id.into();
     }
 
-    println!("Added {} cards for {:?}", stats.len(), time.elapsed());
+    info!("Added {} cards for {:?}", stats.len(), time.elapsed());
 }
 
 pub fn update_stat_score(stat: &CardStatistics, connection: &Connection) {
@@ -70,7 +71,7 @@ pub fn update_stat_score(stat: &CardStatistics, connection: &Connection) {
             (&stat.score, &stat.last_open.timestamp(), &stat.id),
         )
         .unwrap();
-    println!("Updated stat: {}", time.elapsed().as_millis());
+    info!("Updated stat: {}", time.elapsed().as_millis());
 }
 
 pub fn delete_stats(stat: &[CardStatistics], connection: &Connection) {