Small fix to ColorbarPlot when no ranges are supplied
Small fix to ColorbarPlot when no ranges are supplied

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