Rework of the skymap utilities
Replaces the outdated (and potentially incorrect) skymap code with code adapated from ligo.skymap itself. This is incorporated into the CBCResult object as a method, and generated the fits, pickle and skymap.
Replaces the outdated (and potentially incorrect) skymap code with code adapated from ligo.skymap itself. This is incorporated into the CBCResult object as a method, and generated the fits, pickle and skymap.