fix(build): remove prompt confirmation on windows

On Windows, "del dist" didn't use npm package del-cli, but it uses Windows del command which prompts a confirmation.

package.json

@@ -20,7 +20,7 @@
     "node": ">=8.9.0"
   },
   "scripts": {
-    "clean": "del dist",
+    "clean": "rimraf dist",
     "build": "npm run build:ts && npm run build:dts && npm run build:copy-files",
     "build:ts": "tsc",
     "build:ts:watch": "npm run build:ts -- --watch",
@@ -82,7 +82,6 @@
     "aurelia-tools": "^2.0.0",
     "babel-eslint": "^10.0.2",
     "copyfiles": "^2.1.1",
-    "del-cli": "^2.0.0",
     "gulp-bump": "^3.1.3",
     "gulp-clean": "^0.4.0",
     "gulp-conventional-changelog": "^2.0.19",
@@ -96,6 +95,7 @@
     "nodemon": "^1.19.1",
     "nyc": "^14.1.1",
     "puppeteer": "^1.19.0",
+    "rimraf": "^2.6.3",
     "ts-node": "^8.3.0",
     "typescript": "^3.5.3",
     "yargs": "^13.3.0"