Update project skrollr to 0.6.28

libgrabber updated project skrollr to 0.6.28.

@Prinzhorn

### Metadata information

```json
{
  "metadata": {
    "packageManager": "github",
    "name": "skrollr",
    "repo": "Prinzhorn/skrollr",
    "files": {
      "basePath": "dist/",
      "include": ["skrollr.min.js"],
      "exclude": []
    },
    "path": "/home/jsdelivr/files/skrollr",
    "localVersions": ["0.5.13", "0.6.8", "0.6.11", "0.6.21", "0.6.24", "0.6.25", "0.6.26", "0.6.27"],
    "remoteVersions": ["0.5.14", "0.6.0", "0.6.1", "0.6.2", "0.6.3", "0.6.4", "0.6.5", "0.6.6", "0.6.7", "0.6.8", "0.6.9", "0.6.10", "0.6.11", "0.6.12", "0.6.13", "0.6.14", "0.6.15", "0.6.16", "0.6.17", "0.6.18", "0.6.19", "0.6.20", "0.6.21", "0.6.22", "0.6.23", "0.6.24", "0.6.25", "0.6.26", "0.6.27", "0.6.28"],
    "branchVersions": []
  },
  "version": "0.6.28",
  "updated": true,
  "updatePath": "/home/jsdelivr/files/skrollr/0.6.28",
  "branch": "skrollr/0.6.28"
}
```