chore(server): update ts-node and nodemon, remove unused dependencies

Remove underscore and express validator

Use nodemon version 2.0.7

Latest version of nodemon have issue in windows (remy/nodemon#1889).

server/package.json

@@ -15,19 +15,17 @@
     "dotenv": "^8.2.0",
     "express": "^4.16.4",
     "express-session": "^1.16.1",
-    "express-validator": "^6.2.0",
-    "mongoose": "^5.5.4",
-    "underscore": "^1.9.1"
+    "mongoose": "^5.5.4"
   },
   "devDependencies": {
     "eslint": "^5.16.0",
     "eslint-config-airbnb-base": "^13.1.0",
     "eslint-config-prettier": "^4.2.0",
     "eslint-plugin-import": "^2.17.2",
     "eslint-plugin-prettier": "^3.0.1",
-    "nodemon": "^1.19.4",
+    "nodemon": "2.0.7",
     "prettier": "^1.17.0",
-    "ts-node": "^10.0.0",
+    "ts-node": "^10.1.0",
     "typescript": "^4.3.5"
   }
 }