render_label displays special characters incorrectly

[SietzeN]

Hi Tyler,

Thanks for your wonderful package. I noted that when labeling points with render_label(), special characters are not displayed correctly. For example, the letters ã and é are replaced with a square. I've tried using unicode characters ( \u00E3 and \u00E9 respectively), but the result is the same.

Cheers!

[LicanMartinez]

I may be having kind of a similar problem here. When runing render_label() with a spanish accent character (ó) R session crashes.