Removed faulty failsafe in redis_server fixture.

* It didn't work and making it work would require more work than its
  worth right now.
Moved redis_server fixture to plugin.
Lua scripts' Redis calls are no longer faded.

* The RE wasn't macthing the hostname:port pair given to the lua
  scripts' commands (which is just lua).
Made first real unit test.

* I also made all changes required to make it pass (ie: fixing any
  bugs in the register and unregister functions that it uncovered).