添加测试结束后颜色显示, 方便判断, 修复部分Bug

src/download_wrapper.rs

@@ -204,7 +204,7 @@ impl DownloadWrapper {
     }
 
     fn save_log(& self, label: String, log: String) -> Result<bool, DownloadError> {
-        if !fs::exists("./log") {
+        if !fs::exists("./log").unwrap() {
             fs::create_dir("./log").expect("Cant Create Log Folder");
         }
         let mut file = fs::OpenOptions::new()