Pipen

- refactor(frontend): use system.js (instead iife) to chunk vendor libraries
- ci: update ghp-import command to disable Jekyll processing
- deps: update frontend dependencies

**Full Changelog**: https://github.com/pwwang/pipen-report/compare/0.18.5...0.19.0rc1

- feat: indicate number of pages in log message

**Full Changelog**: https://github.com/pwwang/pipen-report/compare/0.18.4...0.18.5

- choir: remove caching for `_render_file()`.
- Template rendering can be dependent on the file contents (e.g. `<job.outdir>/report.json`)

**Full Changelog**: https://github.com/pwwang/pipen-report/compare/0.18.3...0.18.4

- deps: bump pipen to 0.14.3
- fix: fix download button for DataTable
- deps: bump frontend deps

**Full Changelog**: https://github.com/pwwang/pipen-report/compare/0.18.2...0.18.3

- fix: fix error getting image size when path is None

**Full Changelog**: https://github.com/pwwang/pipen-report/compare/0.18.1...0.18.2

- enh: cache template rendering and preprocessing

**Full Changelog**: https://github.com/pwwang/pipen-report/compare/0.18.0...0.18.1