ValueError: keyword grid_b when plotting histograms

[semmyk-research]

Notice an error when calling litstudy.plot_country_histogram(...) and any of the other plots based on plot_histogram
Dug and noticed the error is because of changes in matplotlib.

[observed]
All plots based on plot_histogram() throws: ValueError: keyword grid_b is not recognized
Apparently, this might be due to changes in matplotlib
## reproducibility: python==3.8.16, matplotlib==3.7.1

    ax.grid(b=False, which='both', axis='y')
    xlabel, ylabel = ylabel, xlabel
else:
    ax.grid(b=False, which='both', axis='x')

[stijnh]

Thanks for using litstudy and thanks for the bug report!

This has been fixed as of ee27017