Validate presence of Geo::EventLogState#event_id

app/models/geo/event_log_state.rb

 class Geo::EventLogState < Geo::BaseRegistry
   self.primary_key = :event_id
 
+  validates :event_id, presence: true
+
   def self.last_processed
     order(event_id: :desc).first
   end

spec/models/geo/event_log_state_spec.rb

+require 'spec_helper'
+
+RSpec.describe Geo::EventLogState, type: :model do
+  describe 'validations' do
+    it { is_expected.to validate_presence_of(:project) }
+  end
+end