message: update prague dev server in rush
diff: "private": true,
  "devDependencies": {
  "@microsoft/rush": "^5.5.4",
  - "@prague/prague-dev-server": "^3.2.1",
  + "@prague/prague-dev-server": "^3.2.5",
  "@types/mocha": "^5.2.6",
  "mocha": "^5.2.0",
  "ts-node": "^8.0.2",
  