Get ready for CRAN release v0.3

[andrie]

I'm hoping to release a new version to CRAN within the next few weeks. I'm asking for community input whether there is anything urgent that we should still fix before such a release.

This is the current NEWS file:

• Support for mac.binary.big-sur (Add macOS Big Sur to valid options in repo check #152)
• Rewrite tests to use Posit Public Package Manager, since MRAN ceased to operate their service during 2023

Bug fixes:

• Don't download incorrect devel version of package (miniCRAN::makeRepo downloads R-devel version of a package #153)

Internal:

• Rename internal function MRAN() to p3m() to reflect using Posit Public Package Manager (P3M)

Asking specific input from @achubaty , @vnijs , @ColinFay and @tonytonov because you've opened issues in the past.

[tonytonov]

Hi @andrie, no specific suggestions from me, thank you.

[andrie]

I've submitted v0.3.0 to CRAN. 🤞