Bump gulp-clean from 0.3.2 to 0.4.0

Bumps [gulp-clean](https://github.com/peter-vilja/gulp-clean) from 0.3.2 to 0.4.0.
- [Release notes](https://github.com/peter-vilja/gulp-clean/releases)
- [Commits](peter-vilja/gulp-clean@v0.3.2...v0.4.0)

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

package.json

@@ -47,7 +47,7 @@
     "github": "^9.2.0",
     "gulp": "^3.9.1",
     "gulp-babel": "^6.1.2",
-    "gulp-clean": "^0.3.2",
+    "gulp-clean": "^0.4.0",
     "gulp-concat": "^2.6.1",
     "gulp-htmlmin": "^5.0.1",
     "gulp-iife": "^0.3.0",