The library can be cleared

Oh, and also change all the describe blocks to it blocks. Stupid me.
Testing modifying the goal

Includes a skipped test when Double Agenda is out on the field
Give the shackles test card a set

Delete the player state check, we don't need to do that at all.

Check if the description is nil when there isn't one given. The set should be a
generic 'Fluxx' when a not given one.