Update project rxjs to v2.3.13

libgrabber updated project rxjs to v2.3.13.

@Reactive-Extensions

### Metadata information

```json
{
  "metadata": {
    "packageManager": "github",
    "name": "rxjs",
    "repo": "Reactive-Extensions/RxJS",
    "files": {
      "basePath": "dist/",
      "include": ["*.js"],
      "exclude": []
    },
    "path": "/home/jsdelivr/files/rxjs",
    "localVersions": ["2.1.10", "2.1.11", "2.1.15", "2.1.18", "2.1.20", "2.2.2", "2.2.3", "2.2.7", "2.2.10", "2.2.14", "2.2.15", "2.2.17", "2.2.20", "2.2.24", "2.2.25", "2.2.26", "2.2.27", "2.2.28", "2.3.0", "2.3.1", "2.3.2", "2.3.3", "2.3.4", "2.3.5", "2.3.6", "2.3.7", "2.3.8", "2.3.9", "2.3.10", "2.3.11"],
    "remoteVersions": ["v2.2.13", "v2.2.14", "v2.2.15", "v2.2.16", "v2.2.18", "v2.2.19", "v2.2.20", "v2.2.21", "v2.2.22", "v2.2.23", "v2.2.24", "v2.2.25", "v2.2.26", "v2.2.27", "v2.2.28", "v2.3.0", "v2.3.1", "v2.3.2", "v2.3.3", "v2.3.4", "v2.3.5", "v2.3.6", "v2.3.7", "v2.3.8", "v2.3.9", "v2.3.10", "v2.3.11", "v2.3.12", "v2.3.13"],
    "branchVersions": ["v2.3.12"]
  },
  "version": "v2.3.13",
  "updated": true,
  "updatePath": "/home/jsdelivr/files/rxjs/2.3.13",
  "branch": "rxjs/v2.3.13"
}
```