change package name from gosling -> grosling

[manzt]

from @keller-mark

Another annoying thing about bioconductor if you are thinking about submitting there - the package name must match the github repo name when you do the submission https://contributions.bioconductor.org/package-name.html (again listed as a suggestion here but the github bot enforces it as a requirement 😐)

I like the grosling name a good amount, so why not? I guess it might confuse that it's just a wrapper around Gos. Maybe we change the import namespace from gos to gros? open to other ideas.