Pympc

- Patch fix to correct a mix-up in tags and local version numbers.

- A buffer is applied to `search_radius` when cross-matching prior to calculating topocentric positions. This
is to prevent missing positional matches that are initially outside the search radius, but for which the topocentric
correction brings them within it.
- Add `pyerfa` to requirements to catch dubious year warnings
- [DOCS] Added notebook quantify the degradation of matching with reference epoch separation

- Changelog added!
- Added topocentric corrections.
- Uses the user's system temporary directory by default for downloaded catalogues
instead of hardcoded `/tmp`.
- Add option to `cleanup` argument to `update_catalogue()` to remove downloaded
catalogues after the xephem database is created (default is `True`).
- The filepath of the created xephem database is now returned from `update_catalogue()`.
- Added command line interface via `minor_planet_check`, once package is installed.
- Results from `pympc.minor_planet_check()` are now formatted in an astropy table and
an empty search returns `None` instead of an empy list.
- Added first tests.