Bump vendor/github.com/twbs/bootstrap-rubygem (#131)

Bumps [vendor/github.com/twbs/bootstrap-rubygem](https://github.com/twbs/bootstrap-rubygem) from `1e6b6b2` to `decb961`.
- [Release notes](https://github.com/twbs/bootstrap-rubygem/releases)
- [Commits](twbs/bootstrap-rubygem@1e6b6b2...decb961)

---
updated-dependencies:
- dependency-name: vendor/github.com/twbs/bootstrap-rubygem
  dependency-version: decb9616d0cfb553c2b4bff37a929aa0f69011ec
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]