Set ActiveJob configs and convert WelcomeEnterpriseJob to new format

This needs to be done for all jobs.

Docs: https://guides.rubyonrails.org/v4.2/active_job_basics.html

app/jobs/welcome_enterprise_job.rb

@@ -1,5 +1,5 @@
-WelcomeEnterpriseJob = Struct.new(:enterprise_id) do
-  def perform
+class WelcomeEnterpriseJob < ActiveJob::Base
+  def perform(enterprise_id)
     enterprise = Enterprise.find enterprise_id
     EnterpriseMailer.welcome(enterprise).deliver
   end

app/models/enterprise.rb

@@ -400,7 +400,7 @@ class Enterprise < ActiveRecord::Base
   end
 
   def send_welcome_email
-    Delayed::Job.enqueue WelcomeEnterpriseJob.new(id)
+    WelcomeEnterpriseJob.perform_later(id)
   end
 
   def strip_url(url)

config/application.rb

@@ -199,5 +199,7 @@ module Openfoodnetwork
     config.assets.precompile += ['*.jpg', '*.jpeg', '*.png', '*.gif' '*.svg']
 
     config.active_support.escape_html_entities_in_json = true
+
+    config.active_job.queue_adapter = :delayed_job
   end
 end

config/environments/test.rb

@@ -51,6 +51,8 @@ Openfoodnetwork::Application.configure do
   require 'open_food_network/rack_request_blocker'
   # Make sure the middleware is inserted first in middleware chain
   config.middleware.insert_before('ActionDispatch::Static', 'RackRequestBlocker')
+
+  config.active_job.queue_adapter = :test
 end
 
 # Allows us to use _url helpers in Rspec

spec/jobs/welcome_enterprise_job_spec.rb

@@ -8,6 +8,6 @@ describe WelcomeEnterpriseJob do
     expect(EnterpriseMailer).to receive(:welcome).with(enterprise).and_return(mail)
     expect(mail).to receive(:deliver)
 
-    run_job WelcomeEnterpriseJob.new(enterprise.id)
+    WelcomeEnterpriseJob.perform_now(enterprise.id)
   end
 end