Added device jobs model

db/migrate/20211019160051_create_device_jobs.rb

@@ -0,0 +1,14 @@
+class CreateDeviceJobs < ActiveRecord::Migration[6.1]
+  def change
+    create_table :device_jobs do |t|
+      t.Jobs :references
+      t.Devices :references
+      t.primary_key :id
+      t.integer :job_id
+      t.integer :device_id
+
+      t.timestamps
+      add_index :device_jobs_index, [:job_id, :device_id]
+    end
+  end
+end