Added three unit tests of DynamicMap clone method
Added three unit tests of DynamicMap clone method

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