Rails 6

.travis.yml

@@ -2,11 +2,9 @@ language: ruby
 sudo: false
 cache: bundler
 rvm:
-  - 2.2.9
-  - 2.3.6
-  - 2.4.3
+  - 2.3.8
+  - 2.4.5
   - 2.5.0
-  - rbx
   - jruby-9.1.16.0
 jdk:
   - openjdk7
@@ -45,7 +43,6 @@ matrix:
       gemfile: gemfiles/Gemfile.rails-master
       env: DEVISE_ORM=mongoid
   allow_failures:
-    - rvm: rbx
     - rvm: jruby-9.1.16.0
       gemfile: Gemfile
     - gemfile: gemfiles/Gemfile.rails-master

lib/generators/active_record/devise_invitable_generator.rb

@@ -3,14 +3,14 @@
 module ActiveRecord
   module Generators
     class DeviseInvitableGenerator < ActiveRecord::Generators::Base
-      source_root File.expand_path("../templates", __FILE__)
+      source_root File.expand_path('../templates', __FILE__)
 
       def copy_devise_migration
-        migration_template "migration.rb", "db/migrate/devise_invitable_add_to_#{table_name}.rb", migration_version: migration_version
+        migration_template 'migration.rb', "db/migrate/devise_invitable_add_to_#{table_name}.rb", migration_version: migration_version
       end
 
       def migration_version
-        if Rails.version.start_with? '5.'
+        if Rails::VERSION::MAJOR >= 5
           "[#{Rails::VERSION::MAJOR}.#{Rails::VERSION::MINOR}]"
         end
       end