Check if cowplot::plot_grid is better at aligning than grid.arrange

[juliedwhite]

When there are different spaces taken up by the y-axis (e.g., two digit p-values on the upper plot and one digit p-values on the lower plot), grid.arrange will align based on the y-axis + the y-axis text (see this Stack Overflow post as an example). I'd rather it align based on the y-axis only and just allow the text to shift over as needed. According to the linked post, cowplot::plot_grid might be the fix.