v0.3.1

Internal

• Minor updates to internal code and some unit tests to match forthcoming
  updates to marginaleffects 0.10.0. The latter update also brings some notable
  performance improvements to emfx().

Other

• Some documentation improvements.
• The Examples have been wrapped in \dontrun to avoid triggering CRAN NOTEs on
  Windows for exceeding 5 seconds execution time. Note that the package homepage
  still runs these Examples if users want to inspect the output online.