Resolve "hawaii_2018 Conversion to Zarr"

Closes #52 (closed) Per conversation with @asnyder, I've added the previous attributes to each of the hawaii_ and maui_ zarr datasets. In addition because raw netcdf files I was working with, because the thredds server was shut down, I didn't have a complete description of the projection, so I also fixed the crs variable.

Amelia - please check Fix_attributes.ipynb, and plot_results.ipynb. The latter provides a quick check by plotting a timestep of temperature.

File names are now hawaii_present_1.zarr, hawaii_rcp45_1.zarr, hawaii_rcp85_1.zarr and similar for maui. NOTE I added the _1 file name suffix.