chore(deps-dev): bump gulp from 3.9.1 to 5.0.1

Bumps [gulp](https://github.com/gulpjs/gulp) from 3.9.1 to 5.0.1.
- [Release notes](https://github.com/gulpjs/gulp/releases)
- [Changelog](https://github.com/gulpjs/gulp/blob/master/CHANGELOG.md)
- [Commits](gulpjs/gulp@v3.9.1...v5.0.1)

---
updated-dependencies:
- dependency-name: gulp
  dependency-version: 5.0.1
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package.json

@@ -20,7 +20,7 @@
     "babel-core": "^6.26.3",
     "babel-polyfill": "^6.26.0",
     "babel-preset-es2015": "^6.24.1",
-    "gulp": "^3.9.1",
+    "gulp": "^5.0.1",
     "gulp-babel": "^6.1.2",
     "gulp-cli": "^3.1.0",
     "gulp-concat": "^2.6.1",