/api/stop doesn't return a JSON response anymore

it prevents the following exception:
```
(node:10648) UnhandledPromiseRejectionWarning: SyntaxError: Unexpected end of JSON input
    at JSON.parse (<anonymous>)
    at DaemonCommander.stop
```

src/commander.ts

@@ -59,7 +59,7 @@ export class DaemonCommander {
       };
 
       const {body} = await got(options);
-      return JSON.parse(body);
+      return body;
    }
 
    async delete() {