[xmlunit/xmlunit.net] 5dea90: try an appveyor matrix build

[Stefan B. <no...@gi...>]

  Branch: refs/heads/netstandard-2.0
  Home:   https://github.com/xmlunit/xmlunit.net
  Commit: 5dea90181e12c5c77111e41baf23973968096552
      https://github.com/xmlunit/xmlunit.net/commit/5dea90181e12c5c77111e41baf23973968096552
  Author: Stefan Bodewig <ste...@fr...>
  Date:   2019-04-04 (Thu, 04 Apr 2019)

  Changed paths:
    M appveyor.yml

  Log Message:
  -----------
  try an appveyor matrix build