Ffmpeg-normalize

* Add all commits to changelog.

* Remove python 2 support.

* Add quiet option, fixes 116.

- Add a new quiet option
- Promote some warnings to actual errors that need to be shown
- Add a very basic test case

* Improve release script.

* Python 3.8.

* Only print length warning for non-EBU type normalization.

* Remove build and dist folder on release.

* Do not exit on error in batch processing.

Simply process the next file if one has errors, addresses 110.

* Use minimal dependency for tqdm.

* Remove specific python version requirement.

* Freeze tqdm version.

* Update python to 3.7.

* Improve release documentation.