Add names to SolarSysObjects.
Use SolarSysObject instaed of MovingTarget.
Capitalize Sun, Moon, etc.
Remove MovingTarget.
Simplify date rounding in plot_am.
Merge branch 'new-quanitity-behavior' into dev
Merge branch 'mkflat-bug' into dev
Merge branch 'new-quantity-behavior' into dev
Merge branch 'v2.1.x' into dev
Update to v2.1
v2.1.0
Merge pull request #23 from mkelley/v2.1.x

update to v2.1.0