[R-pkg-devel] .bib file in vignette not found during R CMD check

When building the vignette using R CMD Build or
`devtools::build_vignette()` everything works fine.

However, during R CMD check I get the following

** checking running R code from vignettes ...*
*   ?sperrorest-vignette.Rmd? using ?UTF-8? ... OK*
* NONE*
** checking re-building of vignette outputs ... WARNING*
*Error in re-building vignettes:*
*  ...*
*pandoc-citeproc: Could not find Biblio.bib*
*CallStack (from HasCallStack):*
*  error, called at src/Text/CSL/Pandoc.hs:224:39 in
pandoc-citeproc-0.10.4.1-EdjBizYp62fCPHef3CymGR:Text.CSL.Pandoc*
*pandoc: Error running filter /usr/local/bin/pandoc-citeproc*
*Filter returned error status 1*
*Error: processing vignette 'sperrorest-vignette.Rmd' failed with
diagnostics:*
*pandoc document conversion failed with error 83*
*Execution halted*

The .bib file is lying in `/vignettes`. There is a similar question on SO
<http://stackoverflow.com/questions/41126556/any-way-of-attaching-csl-bib-files-by-using-knitcitations-package>
but
the answer does not address the problem.
When using full paths everything is fine. However, I cannot use full paths
when submitting to CRAN.

If you want to check on your own, please use the `dev` branch;
https://github.com/pat-s/sperrorest/tree/dev

pandoc-citeproc: stable 0.10.4.1 (bottled), HEAD
pandoc: stable 1.19.2.1 (bottled), HEAD