Fix for mpld3 in widgets
Fix for mpld3 in widgets

basnijholt/holoviews,ioam/holoviews,ioam/holoviews,ioam/holoviews,vascotenner/holoviews,vascotenner/holoviews,vascotenner/holoviews,basnijholt/holoviews,basnijholt/holoviews