Variant-extractor

Fix

* fix: Dummy release to generate Zenodo DOI ([`2c890f9`](https://github.com/EUCANCan/variant-extractor/commit/2c890f99f006f74d247262d6cd3e7995e8bb2b16))

Fix

* fix: Remove author from __init__.py ([`2d48c4a`](https://github.com/EUCANCan/variant-extractor/commit/2d48c4a3bcdabb6e2d1842b562ac25f0d2025faa))

Performance

* perf: Reduce dataframe memory footprint ([`011f2bb`](https://github.com/EUCANCan/variant-extractor/commit/011f2bb2612f1b2f7f38701e95919f2b63c3f222))

Fix

* fix: Fix missing fields in str conversion ([`4bbef95`](https://github.com/EUCANCan/variant-extractor/commit/4bbef9546c1c3992a75f3146f67dac0def76c641))

Fix

* fix: Fix Python3.6 typings ([`5b3bdd6`](https://github.com/EUCANCan/variant-extractor/commit/5b3bdd696437747c5a9cf3874392817bdee0f2d7))

Performance

* perf: Improve __str__ performance ([`ec14074`](https://github.com/EUCANCan/variant-extractor/commit/ec140748b5abd31284580c5eacfd7bb2e44cacde))

Performance

* perf: Improve I/O speed by lazy loading fields ([`93782fc`](https://github.com/EUCANCan/variant-extractor/commit/93782fc05585981a3d3ef20a6705e18160486a47))