Gulp: Cleanup dead code

The task for building tutti was never used, since all functionality is
built by pillar.

Also remove the dependencies for jQuery and Bootstrap in package.json

package.json

@@ -22,10 +22,5 @@
 		"gulp-sourcemaps": "~2.6.4",
 		"gulp-uglify-es": "^1.0.4",
 		"minimist": "^1.2.0"
-	},
-	"dependencies": {
-		"bootstrap": "^4.1.3",
-		"jquery": "^3.3.1",
-		"popper.js": "^1.14.4"
 	}
 }