Update package.json template to node 14 Typescript

Update the typescript types.

Author: Duncan Grant

python/rpdk/typescript/templates/package.json

@@ -17,7 +17,7 @@
         "class-transformer": "0.3.1"
     },
     "devDependencies": {
-        "@types/node": "^12.0.0",
+        "@types/node": "^14.0.0",
         "typescript": "^4.1.2"
     },
     "optionalDependencies": {