fix linting

packages/hydrojudge/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@hydrooj/hydrojudge",
-    "version": "2.0.0",
+    "version": "2.0.1",
     "main": "package.json",
     "author": "masnn",
     "os": [

packages/hydrojudge/src/cases.ts

@@ -1,5 +1,4 @@
 import fs from 'fs-extra';
-import yaml from 'js-yaml';
 import path from 'path';
 import { Dictionary } from 'lodash';
 import { FormatError, SystemError } from './error';