Update gulp-uglify requirement from 2.1.2 to 3.0.2

Updates the requirements on [gulp-uglify](https://github.com/terinjokes/gulp-uglify) to permit the latest version.
- [Release notes](https://github.com/terinjokes/gulp-uglify/releases)
- [Changelog](https://github.com/terinjokes/gulp-uglify/blob/master/CHANGELOG.md)
- [Commits](terinjokes/gulp-uglify@v2.1.2...v3.0.2)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

package.json

@@ -32,7 +32,7 @@
     "gulp-sourcemaps": "2.6.0",
     "gulp-stylus": "2.6.0",
     "gulp-svgstore": "6.1.0",
-    "gulp-uglify": "2.1.2",
+    "gulp-uglify": "3.0.2",
     "gulp-util": "3.0.8",
     "jquery": "3.2.1",
     "lazypipe": "1.0.1",