Drop to support fat gem

Gemfile

@@ -1,3 +1,9 @@
 source 'https://rubygems.org'
 
 gemspec
+
+group :development do
+  gem 'rake-compiler', ">= 0.4.1"
+  gem 'minitest', "~> 5.0"
+  gem 'ruby-maven', :platforms => :jruby
+end

Rakefile

@@ -28,21 +28,7 @@ if RUBY_PLATFORM =~ /java/
   end
 else
   require 'rake/extensiontask'
-  spec = Gem::Specification.load("psych.gemspec")
-  Rake::ExtensionTask.new("psych", spec) do |ext|
-    ext.lib_dir = File.join(*['lib', ENV['FAT_DIR']].compact)
-    ext.cross_compile = true
-    ext.cross_platform = %w[x86-mingw32 x64-mingw32]
-    ext.cross_compiling do |s|
-      s.files.concat ["lib/2.3/psych.so", "lib/2.4/psych.so", "lib/2.5/psych.so"]
-    end
-  end
-end
-
-desc "Compile binaries for mingw platform using rake-compiler-dock"
-task 'build:mingw' do
-  require 'rake_compiler_dock'
-  RakeCompilerDock.sh "bundle && rake cross native gem RUBY_CC_VERSION=2.5.0:2.4.0:2.3.0"
+  Rake::ExtensionTask.new("psych")
 end
 
 task :default => [:compile, :test]

lib/psych.rb

@@ -10,11 +10,7 @@
     org.jruby.ext.psych.PsychLibrary.new.load(JRuby.runtime, false)
   end
 else
-  begin
-    require "#{RUBY_VERSION[/\d+\.\d+/]}/psych.so"
-  rescue LoadError
-    require 'psych.so'
-  end
+  require 'psych.so'
 end
 require 'psych/nodes'
 require 'psych/streaming'

psych.gemspec

@@ -51,9 +51,6 @@ DESCRIPTION
   s.rubygems_version = "2.5.1"
   s.required_rubygems_version = Gem::Requirement.new(">= 0")
 
-  s.add_development_dependency 'rake-compiler', ">= 0.4.1"
-  s.add_development_dependency 'minitest', "~> 5.0"
-
   if RUBY_ENGINE == 'jruby'
     s.platform = 'java'
     s.files.concat [
@@ -67,9 +64,7 @@ DESCRIPTION
     ]
     s.requirements = "jar org.yaml:snakeyaml, #{Psych::DEFAULT_SNAKEYAML_VERSION}"
     s.add_dependency 'jar-dependencies', '>= 0.1.7'
-    s.add_development_dependency 'ruby-maven'
   else
     s.extensions = ["ext/psych/extconf.rb"]
-    s.add_development_dependency 'rake-compiler-dock', ">= 0.6.3"
   end
 end