pysal/giddy: giddy 2.0.0

This release does not add any new functionality to giddy, but instead features api changes in giddy and its pysal submodule dependencies mapclassify, libpysal, and esda. More specifically, the giddy.api module which was originally designed to facilitate a smoother transition from the old metapackage pysal to the refactored submodule structure (see here for details) was removed as we are moving away from the refactoring stage and looking at the future development