add zone test-rspec

spec/models/zone_spec.rb

@@ -1,5 +1,11 @@
 require 'rails_helper'
 
 RSpec.describe Zone, type: :model do
-  pending "add some examples to (or delete) #{__FILE__}"
+ # Association test
+ # ensure Todo model has a 1:m relationship with the Item model
+ it { should have_many(:seat_tables).dependent(:destroy) }
+ # Validation tests
+ # ensure columns title and created_by are present before saving
+ it { should validate_presence_of(:name) }
+ it { should validate_presence_of(:created_by) }
 end