Add an option for a shutdown script.
Whoops, include the  parameter in the openvpn::server class definition.
Enclose the 'up' and 'down' settings in the server's configuration file in double quotes to allow for scripts with arguments.
add tests for up/down handling
Merge pull request #75 from luxflux/CtrlC-Root-master

Ability to specify a `down` script, fixes #74