Py50

Bug fixes 🪲

**Calculator**
- Modified the initial guesses for curve fitting for the 4PL equation. Previously input assumed IC50 value to be 1.0. The initial guesses have been modified as follows:
- Max response
- Min response
- 0.5 * (max(response) + min(response))
- slope (1.0)

Bug fixes 🪲

**Calculator**
- Increased maxfev to allow more calls to the curvefit() function

Bug fixes 🪲

**PlotCurve**
- Fixed box highlight in grid_curve_plot()
- Box was not highlighting properly with the introduction of ymax and ymin
- Code has been reformatted to avoid these issues

Bug fixes 🪳

**PlotCurve**
- Fixed ylimit argument.
- Now include ymax and ymin to manually adjust the length of the y-axis.

Bug fixes 🪳

**Calculations**
- Fixed pIC50 calculation to function with nM or µM units.

**Calculations**
- Added ability to scale IC50 values into pIC50 values. This is done using the calculate_pic50() function, which utilizes the calculate_absolute_ic50() function.

**Plot_Curves**
- Turned off grid lines by default.
- Included **kwargs for matplotlib.
- For now, only (grid=True/False) arguments will work and will control the plotting of grid lines.
- Automatic grid lines may be due to the matplotlib version