[GRASS-git] [OSGeo/grass] 400c59: docker version matrix: update Alpine version

[Markus Neteler]

  Branch: refs/heads/releasebranch_7_8
  Home:   https://github.com/OSGeo/grass
  Commit: 400c59749c709ab1420fd2b10f9016c38c17290c
      https://github.com/OSGeo/grass/commit/400c59749c709ab1420fd2b10f9016c38c17290c
  Author: Markus Neteler <neteler at gmail.com>
  Date:   2020-09-17 (Thu, 17 Sep 2020)

  Changed paths:
    M docker/README.md

  Log Message:
  -----------
  docker version matrix: update Alpine version