chore(release): 3.13.1

## [3.13.1](https://gitlab.tsn.tno.nl/ci/templates/compare/v3.13.0...v3.13.1) (2021-07-21)

### Bug Fixes

* ensure no variables are set ([748ac375](https://gitlab.tsn.tno.nl/ci/templates/commit/748ac3756a89a83d621723ad1e1759542150d3aa))