Eprints2bags

This version fixes a minor error in `CITATION.cff`.

This version only updates information in `CITATION.cff`, `codemeta.json`, and a few other files. There are no functional changes in this release.

Changes in this version:
* Fix reference to wrong exception name in network code.
* Add missing import of `aenum` to `requirements.txt`

* Removed delay option `-y`. Servers should probably implement throttling if rates are a problem, and anyway, the default value was probably too short to be of any use, so it's unlikely this option was of any use anyway.
* Switched to using `cpu_count()` from Python `os` package instead of our own custom code.
* Switched to using [Sidetrack](https://github.com/caltechlibrary/sidetrack) instead of original internal debug logging code.
* Switched to using [Bun](https://github.com/caltechlibrary/bun) for basic terminal output.
* Switched to using [CommonPy](https://github.com/caltechlibrary/commonpy) for common utilities.
* Internally, use different approach to recording version number and other metadata.
* Updated and refactored `Makefile`.
* Added `CITATION.cff` file.
* Refactored and update internal code.
* Renamed branch `master` to `main`.

* **Critical bug fix**: in a version of Python after 3.5, the behavior of getting raw data via the [requests](http://docs.python-requests.org) package changed in a way that caused `eprints2bags` to write zero-length data files to disk. This version changes internal code to avoid the problem that causes this.
* Report missing and skipped records separately at the end, instead of calling everything "missing".

* Update installation instructions in README.md to explain how to install from PyPI, and make README file more compatible with displaying it on PyPI.
* Fix PyPI-related issues in `setup.cfg`.
* Fix configuration bug in `setup.py`.