- The formula that calculates ρ (mass density of soils) from Vs (shear wave velocity) is updated: log10 is used instead of log (natural logatirhm). See the updated code [here](https://github.com/jsh9/PySeismoSoil/blob/56609cd124aabe664e78aa679c8dfcdbe10224b2/PySeismoSoil/helper_hh_calibration.py#L760-L765). This is to correct a mistake in notation in Mayne et al. (1999).
- Python 3.6 is no longer supported.