Impedance

What's Changed
* Adds Zarc element by etrevis in https://github.com/ECSHackWeek/impedance.py/pull/268

New Contributors
* etrevis made their first contribution in https://github.com/ECSHackWeek/impedance.py/pull/268

**Full Changelog**: https://github.com/ECSHackWeek/impedance.py/compare/v1.6.0...v1.7.0

What's Changed
* changes TLMQ element equation to make Zs match the paper, fixes 253 by mdmurbach in https://github.com/ECSHackWeek/impedance.py/pull/255
* Replaces .append with pd.concat, fixes 264 by mdmurbach in https://github.com/ECSHackWeek/impedance.py/pull/265

**Full Changelog**: https://github.com/ECSHackWeek/impedance.py/compare/v1.5.0...v1.6.0

What's Changed
* Custom circuit elements using element decorator 🍰 rgasper in 196
* Bug fixes to properly handle spaces and single elements in custom circuit strings 🪓 mdmurbach in 246, 247
* Documentation and example improvements ✏️ pililac in 252 and mdmurbach in 249
* Support matplotlib >= 3.5 by renaming Axes.grid visible kwarg 🦠 mdmurbach in 254

New Contributors
* rgasper made their first contribution in https://github.com/ECSHackWeek/impedance.py/pull/196
* pililac made their first contribution in https://github.com/ECSHackWeek/impedance.py/pull/252

**Full Changelog**: https://github.com/ECSHackWeek/impedance.py/compare/v1.4.3...v1.5.0

What's Changed
kevinsmia1939 fixed incorrect naming in the preprocessing docstrings 📖
oslopanda made bode/nyquist plots more flexible by allowing customizing label/title size 📈
oslopanda fixed a bug in how constants were parsed during fitting 🐞

New Contributors
* kevinsmia1939 made their first contribution in https://github.com/ECSHackWeek/impedance.py/pull/233
* oslopanda made their first contribution in https://github.com/ECSHackWeek/impedance.py/pull/237

**Full Changelog**: https://github.com/ECSHackWeek/impedance.py/compare/v1.4.2...v1.4.3

Fixes several small bugs:
- issues with np.complex for numpy versions > 1.20 (236, 220). Thanks SaftMacki for the fix and oslopanda and pililac for pointing out the issues! ☄️
- max_M could be off by one in linKK tests. Thanks markbouman! 🧪
- frequency and impedance inputs can now be np.array in addition to list. Thanks edmundsj for the suggestion!

Also added publishing to PyPI via GitHub Actions (so hopefully these releases come faster and can be made by more folks) and removed support for [EOL Python v3.6](https://devguide.python.org/versions/)