Fixes #17446 - Provide cloudapp.net domain by default

Since Azure assigns that domain by default to all hosts, it makes sense
for the plugin to add this domain (w/o proxies associated) to Foreman so
people can use it.

db/seeds.d/70-cloudapp-domain.rb

@@ -0,0 +1,4 @@
+domain = Domain.where(:name => 'cloudapp.net').first_or_create
+if domain.nil? || domain.errors.any?
+  raise "Unable to create domain: #{format_errors domain}"
+end

lib/foreman_azure/engine.rb

@@ -30,6 +30,12 @@ class Engine < ::Rails::Engine
         { :assets => { :precompile => ['foreman_azure/host_os_azure_selected.js'] } }
     end
 
+    initializer 'foreman_azure.load_app_instance_data' do |app|
+      ForemanAzure::Engine.paths['db/migrate'].existent.each do |path|
+        app.config.paths['db/migrate'] << path
+      end
+    end
+
     config.to_prepare do
       require 'fog/azure'
       require 'fog/azure/models/compute/servers'