Fix deepcopy & pickle for unsaved model instances & empty image fields (

#324)

Fix #229 -- Delete old file after validation is passed

Previously files were deleted even if the from validation failed.

Co-Authored-By: codingjoe <[email protected]>

Add deprecation warning and migration notes.

Update release action

Bump black from 22.1.0 to 22.3.0

Bumps [black](https://github.com/psf/black) from 22.1.0 to 22.3.0.
- [Release notes](https://github.com/psf/black/releases)
- [Changelog](https://github.com/psf/black/blob/main/CHANGES.md)
- [Commits](psf/black@22.1.0...22.3.0)

---
updated-dependencies:
- dependency-name: black
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Fix multiple jpeg file conversion

Remove progressbar dependency

Fix #224 -- delete_orphans independent from blank (#225)

Remove travis-ci badge

Set file stream curstor to zero position after running validators (#218)

The `BaseSizeValidator` read the file stream to create an in memory Pillow Image object. In reading the file, the file streams cursor was set to the end. Therefore, the validator left the file in a different state than receiving it. This patch sets the cursor back to zero after reading the file.