Update easy-thumbnails requirement from ~=2.7 to ~=2.8
Update easy-thumbnails requirement from ~=2.7 to ~=2.8

Updates the requirements on [easy-thumbnails](https://github.com/SmileyChris/easy-thumbnails) to permit the latest version.
- [Release notes](https://github.com/SmileyChris/easy-thumbnails/releases)
- [Changelog](https://github.com/SmileyChris/easy-thumbnails/blob/master/CHANGES.rst)
- [Commits](https://github.com/SmileyChris/easy-thumbnails/compare/2.7.0...2.8.0)

---
updated-dependencies:
- dependency-name: easy-thumbnails
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
petervanderdoes/wger,wger-project/wger,wger-project/wger,wger-project/wger,petervanderdoes/wger,petervanderdoes/wger,petervanderdoes/wger,wger-project/wger