Wait shutdown in test

test/mute.ts

@@ -12,7 +12,7 @@ process.env.NODE_ENV = 'test';
 
 import * as assert from 'assert';
 import * as childProcess from 'child_process';
-import { async, signup, request, post, react, connectStream, launchServer } from './utils';
+import { async, signup, request, post, react, connectStream, launchServer, shutdownServer } from './utils';
 
 describe('Mute', () => {
 	let p: childProcess.ChildProcess;
@@ -28,8 +28,8 @@ describe('Mute', () => {
 		carol = await signup({ username: 'carol' });
 	}));
 
-	after(() => {
-		p.kill();
+	after(async () => {
+		await shutdownServer(p);
 	});
 
 	it('ミュート作成', async(async () => {