Advent-cli

Changes
Features
- `stats` command will now default to the previous year if current month is before December

[Full changelog](https://github.com/fergusch/advent-cli/commits/v0.2.2)

Changes
Features
- Added conversion of inline `<em>` tags
- Added error messages if session cookie is invalid or expired
- `countdown` now returns a non-zero exit code if aborted, preventing any `get` commands chained with `&&` from running

[Full changelog](https://github.com/fergusch/advent-cli/commits/v0.2.1)

Changes
Features
- Added `countdown` command
- Added config options for converting `<em>` tags to markdown
- Private leaderboards owned by the user are now supported
- `stats` command now defaults to the current year if not specified
Bug fixes
- Fixed a layout issue when displaying private leaderboards

[Full changelog](https://github.com/fergusch/advent-cli/commits/v0.2.0)

Changes
Features
- **advent-cli** is now on [PyPI](https://pypi.org/project/advent-cli/)! 🎉
- Improved error handling
Bug fixes
- Fixed an issue where `--version` would output `__main__` instead of `advent-cli` when run with `python -m`
- Fixed an issue where `submit` would overwrite part 1 in `prompt.md` after downloading part 2
- Fixed an issue where `pip` would not install requirements due to a typo in `setup.cfg`
- Fixed an issue where `get` would not create directories

Other
- Lowered minimum Python version to 3.7
- Added unit tests

[Full changelog](https://github.com/fergusch/advent-cli/commits/v0.1.1)