validate zoom meeting url

spec/models/casting_call_interview_spec.rb

@@ -1,6 +1,7 @@
 require 'rails_helper'
 
 RSpec.describe CastingCallInterview, type: :model do
+  subject { build(:casting_call_interview) }
   describe "associations" do
     it { is_expected.to belong_to(:casting_call) }
     it { is_expected.to have_secure_token(:token) }