[zanata/zanata-server] 08e2ac: Mention MySQL 5.5 specifically

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/zanata/zanata-server
  Commit: 08e2ac3ce9bbbc44b5f67fd0181fa8b3dfafdc8e
      https://github.com/zanata/zanata-server/commit/08e2ac3ce9bbbc44b5f67fd0181fa8b3dfafdc8e
  Author: Sean Flanigan <sflaniga at redhat.com>
  Date:   2015-03-31 (Tue, 31 Mar 2015)

  Changed paths:
    M docs/configuration/installation.md

  Log Message:
  -----------
  Mention MySQL 5.5 specifically