Version 0.5.0

This is a major release that includes bug fixes, changes to default behavior, and enhancements.

Features:

• Widget handling capabilities to facilitate interactivity (#323, #331)
• New default colormaps (#258, #316, #206)
• long_name(units) used to label xarray objects (#173)
• Derived datetime accessor handlind ( #263, #286)
• coastline and tiles options for easy geo plots.
• Automatic date sorting (#259)
• Allow use of strings as aggregators for datashader (#257)

For a full list of changes see: v0.4.0...v0.5.0