pyproj4/pyproj: 2.4.1 Release

Changes Wheels contain PROJ version is 6.2.1 (issue #456) Wheels for Linux x86_64 use manylinux2010 (pyproj4/pyproj-wheels/pull/18) BUG: Fix setting lat_ts for mercator projection in CRS.from_cf() and CRS.to_cf() (issue #461) BUG: latlon -> longlat in CRS.from_cf() for o_proj so behavior consistent in PROJ 6.2.0 and 6.2.1 (pull #472) ENH: Add repr for pyproj.crs.CoordinateOperation and for pyproj.transformer.TransformerGroup (pull #464) Acknowledgements Thanks to everyone who contributed to this release! The detailed bug reports are definitely appreciated. Additionally, thanks to those who help with the distribution! A total of 3 people contributed to the codebase in this release. People with a "+" by their names contributed a patch for the first time: Kristian Evers + Alan D. Snow Other contributions: Christoph Gohlke - testing the Windows wheel builds. Bas Couwenberg - testing the builds with Debian