Update package.json

package.json

@@ -6,7 +6,8 @@
   "dependencies": {
     "react": "^16.6.3",
     "react-dom": "^16.6.3",
-    "react-scripts": "2.1.1"
+    "react-scripts": "2.1.1",
+    "terser": "3.14.1"
   },
   "scripts": {
     "start": "react-scripts start",