Remove Robust Genetics

Robust Genetics no longer makes sense in Alpha.  In fact I would argue that Alpha needs a mutation that makes it harder to get non alpha mutations. Tier 1 Alpha mutation that is most likely your first mutation to get in Alpha and a post thresh version that randomly removes non-alpha mutations once a month.

data/json/mutations/mutations.json

@@ -1203,7 +1203,7 @@
     "description": "Your genome has rapidly adapted to the Cataclysm and can handle the strain of mutation better.  Taking different kinds of mutagen won't result in more defective mutations than normal.",
     "starting_trait": true,
     "cancels": [ "CHAOTIC_BAD" ],
-    "category": [ "FISH", "SLIME", "ALPHA", "MEDICAL", "PLANT" ]
+    "category": [ "FISH", "SLIME", "MEDICAL", "PLANT" ]
   },
   {
     "type": "mutation",