Update gulp-tar requirement from ^1.9.0 to ^2.1.0

Updates the requirements on [gulp-tar](https://github.com/sindresorhus/gulp-tar) to permit the latest version.
- [Release notes](https://github.com/sindresorhus/gulp-tar/releases)
- [Commits](sindresorhus/gulp-tar@v1.9.0...v2.1.0)

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

package.json

@@ -46,7 +46,7 @@
     "gulp-nodemon": "^2.1.0",
     "gulp-sass": "^2.3.2",
     "gulp-sourcemaps": "^1.6.0",
-    "gulp-tar": "^1.9.0",
+    "gulp-tar": "^2.1.0",
     "gulp-template": "^4.0.0",
     "gulp-uglify": "^1.5.4",
     "gulp-useref": "^3.1.0",