to roll out new sp and rgdal, the next things have to be done

• compare reverse dependencies against sp & rgdal released RSB GDAL 2.4.4 PROJ 5.2.0
• compare reverse dependencies against sp & rgdal devel RSB GDAL 3.0.3/PROJ 6.3.0 (st_630_303_200117.zip)
• ?check against PROJ 7 release candidates
• submit to CRAN
• contribute to sf r-spatial blog TODO for CRS changes r-spatial/sf#1244
• inform twitter