[logback-dev] [qos-ch/logback] d8f830: Update CONTRIBUTING.md

[Tony Trinh]

  Branch: refs/heads/master
  Home:   https://github.com/qos-ch/logback
  Commit: d8f830c257da52c1ba07a1af53997ebb1d5f71da
      https://github.com/qos-ch/logback/commit/d8f830c257da52c1ba07a1af53997ebb1d5f71da
  Author: Tony Trinh <tony19 at gmail.com>
  Date:   2014-12-20 (Sat, 20 Dec 2014)

  Changed paths:
    M CONTRIBUTING.md

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