add ruby 2.4.0 and drop rails 4.0. prep v6.4.0.

Author: mceachen

.travis.yml

@@ -2,14 +2,14 @@ cache: bundler
 sudo: false
 language: ruby
 rvm:
-  - 2.3.1
-  - 2.2.5
+  - 2.4.0
+  - 2.3.3
+  - 2.2.6
 # these haven't been passing for a while:
 #  - jruby-head
 #  - rbx
 
 gemfile:
-  - gemfiles/activerecord_4.1.gemfile
   - gemfiles/activerecord_4.2.gemfile
   - gemfiles/activerecord_5.0_foreigner.gemfile
   - gemfiles/activerecord_5.0.gemfile

Appraisals

@@ -1,10 +1,3 @@
-appraise 'activerecord-4.1' do
-  gem 'activerecord', '~> 4.1.0'
-  gem 'foreigner'
-  platforms :ruby, :rbx do
-    gem 'mysql2', '~> 0.3.20'
-  end
-end
 
 appraise 'activerecord-4.2' do
   gem 'activerecord', '~> 4.2.0'

CHANGELOG.md

@@ -1,5 +1,10 @@
 # Changelog
 
+### 6.4.0
+
+* Merged [PR 236](https://github.com/mceachen/closure_tree/pull/236) which adds documentation for `has_closure_tree_root`.
+* Added ruby 2.4 and dropped Rails 4.1 from the build matrix.
+
 ### 6.3.0
 
 * `prepend_child` [handles invalid children properly now](https://github.com/mceachen/closure_tree/issues/249).

README.md

@@ -27,7 +27,7 @@ closure_tree has some great features:
   * 2 SQL INSERTs on node creation
   * 3 SQL INSERT/UPDATEs on node reparenting
 * __Support for [concurrency](#concurrency)__ (using [with_advisory_lock](https://github.com/mceachen/with_advisory_lock))
-* __Support for ActiveRecord 4.1, 4.2 and 5.0__
+* __Support for ActiveRecord 4.2 and 5.0__
 * __Support for Ruby 2.2 and 2.3__
 * Support for reparenting children (and all their descendants)
 * Support for [single-table inheritance (STI)](#sti) within the hierarchy

gemfiles/activerecord_4.1.gemfile

@@ -5,7 +5,7 @@ source "https://rubygems.org"
 gem "activerecord", "~> 4.2.0"
 
 platforms :ruby, :rbx do
-  gem "mysql2", "~> 0.3.20"
+  gem "mysql2"
   gem "pg"
   gem "sqlite3"
 end