fix missing ts-loader in package.json

Author: codetalks-new

client/package.json

@@ -2,6 +2,7 @@
   "private": true,
   "devDependencies": {
     "css-loader": "^0.28.11",
+    "ts-loader": "^4.2.0",
     "typescript": "^2.8.3",
     "vue-loader": "^15.0.6",
     "vue-style-loader": "^4.1.0",