fix: test 명령어 환경 변수 수정

Author: iyu88

frontend/package.json

@@ -10,7 +10,7 @@
     "start": "react-scripts start",
     "start:dev": "env-cmd -f .env.development react-scripts start",
     "build": "env-cmd -f .env.production react-scripts build",
-    "test": "react-scripts test",
+    "test": "env-cmd -f .env.development react-scripts test",
     "eject": "react-scripts eject",
     "electron": "electron .",
     "electron:dev": "concurrently 'npm run start:dev' 'wait-on http://localhost:3000 && electron .'",