Drop support for ruby 2.3

Author: grzegorz-jakubiak

.travis.yml

@@ -6,8 +6,7 @@ before_install:
   - gem install bundler
   - bundle update --bundler
 rvm:
-  - 2.3
   - 2.4
   - 2.5
-  - 2.6  
+  - 2.6
   - 2.7

README.md

@@ -6,8 +6,8 @@
 
 ActiveAdmin is holding off on pulling Mongoid support into the core ActiveAdmin application.  This repo was pulled into the ActiveAdmin org from previous work done by Elia Schito, and will be maintained by Grzegorz Jakubiak, Nic Boie, JD Guzman, Elia Schito and other ActiveAdmin and community members.
 
-### Requirements for version 0.9.0
-* Ruby 2.3.0 or greater. (Note, ruby-2.4.0 fails specs, see [this issue](https://github.com/DatabaseCleaner/database_cleaner/issues/466))
+### Requirements for version 1.0.0
+* Ruby 2.4.0 or greater.
 * Tested working on Rails 5.2.3
 * Mongoid 6.x (**WARNING**:, using a Mongoid version >= 6.1.x has resulted in a fair amount of errors seen in the wild.  Test your upgrade very carefully with any apps in which you're using this gem with Mongoid >= 6.1.x!)
 * ActiveAdmin 1.4.3

activeadmin-mongoid.gemspec

@@ -17,8 +17,8 @@ Gem::Specification.new do |gem|
   gem.require_paths = ['lib']
   gem.version       = ActiveAdmin::Mongoid::VERSION
   gem.license       = 'MIT'
-  
-  gem.required_ruby_version = '>= 2.3'
+
+  gem.required_ruby_version = '>= 2.4'
 
   gem.add_runtime_dependency 'mongoid',     ['~> 6.0']
   gem.add_runtime_dependency 'activeadmin', '>= 1.4.3'

lib/active_admin/mongoid/version.rb

@@ -1,5 +1,5 @@
 module ActiveAdmin
   module Mongoid
-    VERSION = '0.9.0'
+    VERSION = '1.0.0'
   end
 end