[Bioc-devel] Reference inst/extdata files in vignette

Hi all,

I'm working on the development of MungeSumstats(https://github.com/neurogenomics/MungeSumstats) and am trying to reference raw data files (txt and VCF) in my vignette. These files are stored in `inst/extdata` but when I try load then with the below it fails on Bioconductor checks but will pass local checks:

```
eduAttainOkbayPth <- system.file("extdata","eduAttainOkbay.txt", package="MungeSumstats")

reformatted <-   MungeSumstats::format_sumstats(path=eduAttainOkbayPth,ref_genome="GRCh37")
```
The error is caused by a validation check I have to ensure the path passed to `format_sumstats` is valid. Locally this works (see below) but I get an error on Bioconductor:

```

file.exists(eduAttainOkbayPth)[1]

TRUE
```

Does anyone know of the correct way to access raw data files like text files?

Kind regards,
Alan.