fixed time="2014-12-18T07:38:15-05:00" level="fatal" msg="Error response from daemon: Cannot start container e25085e7466b4af83e9eb5e2640099589c29154f3a5a6e4aec38a99bda8d53dd: exec: \"exit\": executable file not found in $PATH"
also reported here https://github.com/hughfletcher/dokku-mysql-plugin/pull/9#issuecomment-48797584
and fixed in the mariadb fork https://github.com/Kloadut/dokku-md-plugin/commit/2fd11ebf4e5ceadbfb1771d48eec086141b27497