[logback-dev] [qos-ch/logback] afc595: Update CONTRIBUTING.md

[Tony Trinh]

  Branch: refs/heads/master
  Home:   https://github.com/qos-ch/logback
  Commit: afc5955189d9391c1ae451a1bc36e4a00ed1660f
      https://github.com/qos-ch/logback/commit/afc5955189d9391c1ae451a1bc36e4a00ed1660f
  Author: Tony Trinh <tony19 at gmail.com>
  Date:   2014-03-30 (Sun, 30 Mar 2014)

  Changed paths:
    M CONTRIBUTING.md

  Log Message:
  -----------
  Update CONTRIBUTING.md