Refactoring loading of config file

- let `HuskConfig::load` return a `Result` instead of an `Option`.
- added comments

src/main.rs

@@ -17,13 +17,13 @@ use daemon::Daemon;
 async fn main() {
 
     let config_file = env::args().nth(1).expect("config file missing");
-    let husk_config = HuskConfig::load(&config_file);
-
-    if husk_config.is_none() {
-        eprintln!("Cannot load configuration");
-        process::exit(1);
-    }
-    let husk_config = husk_config.unwrap();
+    let husk_config = match HuskConfig::load(&config_file) {
+        Ok(config) => config,
+        Err(e) => {
+            eprintln!("{:?}", e);
+            process::exit(1);
+        }
+    };
 
     log4rs::init_file(husk_config.logfile_config(), Default::default()).unwrap();