[GRASS-git] [OSGeo/grass] bbbf83: Add CentOS build check to CI (#604)

[Vaclav Petras]

  Branch: refs/heads/master
  Home:   https://github.com/OSGeo/grass
  Commit: bbbf8364c984978cba725c32f65dd714ba637526
      https://github.com/OSGeo/grass/commit/bbbf8364c984978cba725c32f65dd714ba637526
  Author: Vaclav Petras <wenzeslaus at gmail.com>
  Date:   2020-05-12 (Tue, 12 May 2020)

  Changed paths:
    A .github/workflows/build_centos.sh
    A .github/workflows/centos.yml
    A .github/workflows/yum.txt

  Log Message:
  -----------
  Add CentOS build check to CI (#604)

This uses Docker to run CentOS 7 and then conda to get Python 3 and Python packages. A CentOS-specific build script is used to have a separate configuration.