Update project lunr.js to v0.5.7

libgrabber updated project lunr.js to v0.5.7.

@olivernn

### Metadata information

```json
{
  "metadata": {
    "packageManager": "github",
    "name": "lunr.js",
    "repo": "olivernn/lunr.js",
    "files": {
      "include": ["lunr.min.js"],
      "exclude": []
    },
    "path": "/home/jsdelivr/files/lunr",
    "localVersions": ["0.5.3", "0.5.6"],
    "remoteVersions": ["v0.1.0", "v0.1.1", "v0.2.0", "v0.2.1", "v0.2.2", "v0.2.3", "v0.3.0", "v0.3.1", "v0.3.2", "v0.3.3", "v0.4.0", "v0.4.1", "v0.4.2", "v0.4.3", "v0.4.4", "v0.4.5", "v0.5.0", "v0.5.1", "v0.5.2", "v0.5.3", "v0.5.4", "v0.5.5", "v0.5.6", "v0.5.7"],
    "branchVersions": []
  },
  "version": "v0.5.7",
  "updated": true,
  "updatePath": "/home/jsdelivr/files/lunr/0.5.7",
  "branch": "lunr.js/v0.5.7"
}
```