feat: Save automation rules (#3359)

db/migrate/20211110101046_create_automation_rules.rb

@@ -0,0 +1,14 @@
+class CreateAutomationRules < ActiveRecord::Migration[6.1]
+  def change
+    create_table :automation_rules do |t|
+      t.bigint :account_id, null: false
+      t.string :name, null: false
+      t.text :description
+      t.string :event_name, null: false
+      t.jsonb :conditions, null: false, default: '{}'
+      t.jsonb :actions, null: false, default: '{}'
+      t.timestamps
+      t.index :account_id, name: 'index_automation_rules_on_account_id'
+    end
+  end
+end