add creature and base rp_world

app/models/wow_creature_family.rb

@@ -0,0 +1,9 @@
+class WowCreatureFamily < ApplicationRecord
+  extend Mobility
+  translates :name
+
+  has_many :wow_creatures, dependent: :destroy
+
+  validates :name, presence: true
+  validates :creature_family_id, presence: true, uniqueness: true
+end