ocelot 0.2-alpha

• A wide range of interpolation options were added, allowing isochrones and CMDs to be interpolated.
• A framework was implemented that could be built on to measure the scatter about a spline fit to a CMD, but over time this was deemed not worth the effort (and not very effective.) For the time being, the code will remain in the unit.
• Various QoL improvements and unit testing added for the ocelot.plot submodule.