Remove unnecessary web-vitals and jest.

package.json

@@ -3,10 +3,8 @@
   "version": "0.1.0",
   "private": true,
   "dependencies": {
-    "@testing-library/jest-dom": "^5.11.4",
     "@testing-library/react": "^11.1.0",
     "@testing-library/user-event": "^12.1.10",
-    "@types/jest": "^26.0.15",
     "@types/node": "^12.0.0",
     "@types/react": "^17.0.0",
     "@types/react-dom": "^17.0.0",
@@ -16,8 +14,7 @@
     "react-dom": "^17.0.2",
     "react-router-dom": "^5.3.0",
     "react-scripts": "4.0.3",
-    "typescript": "^4.1.2",
-    "web-vitals": "^1.0.1"
+    "typescript": "^4.1.2"
   },
   "scripts": {
     "start": "react-scripts start",
@@ -27,8 +24,7 @@
   },
   "eslintConfig": {
     "extends": [
-      "react-app",
-      "react-app/jest"
+      "react-app"
     ]
   },
   "browserslist": {