Adds a Space Gym Vault

Created by: Arthurdentist

This PR adds a new vault to the game, the 'gym'.

The gym has two unique 'gym loot' spawners and a standard maint loot spawner. It also has a unique Darkholme suit named 'jabroni outfit' as well as a pill bottle full of creatine 'gym supplements' There is an issue with the pills which I need to resolve before it can be merged but that shouldn't be too tricky. The gym is protected by three unique zombies; Leatherman, Boss of this Gym and Boy Next Door.

This isn't finished yet and i'm looking for suggestions for loot and other things. Its loot is pretty weak compared to the other vaults but im not sure what else to add, if anything.