Bump jbuilder to 2.6.4
Bump jbuilder to 2.6.4

Bumps [jbuilder](https://github.com/rails/jbuilder) from 2.2.5 to 2.6.4.
- [Changelog](https://github.com/rails/jbuilder/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rails/jbuilder/compare/v2.2.5...v2.6.4)
theodi/git-data-viewer,theodi/git-data-viewer,theodi/git-data-viewer