Ioam/Holoviews: Version 1.9.2

This release is a minor bug fix release patching various issues which were found in the 1.9.1 release. Enhancements: Improved the Graph element, optimizing the constructor and adding support for defining a edge_color_index (#2145) Added support for adding jitter to bokeh Scatter and Points plots (e56208) Fixes: Ensure dimensions, group and label are inherited when casting Image to QuadMesh (#2144) Handle compatibility for bokeh version >= 0.12.11 (#2159) Fixed broken bokeh ArrowPlot (#2172) Fixed Pointer based streams on datetime axes (#2179) Allow constructing and plotting of empty Distribution and Bivariate elements (#2190) Added support for hover info on bokeh BoxWhisker plots (#2187) Fixed bug attaching streams to (Nd)Overlay types (#2194)