Remove rake-compiler in favor of manual step

The manual rake definitions allow us to skip the compile process if the
.bundle file is up to date.

.gitignore

@@ -1,3 +1,6 @@
 .ruby-version
-lib/*.bundle
+Makefile
+*.bundle
+*.o
+*.log
 tmp/

Gemfile

@@ -1,6 +1,5 @@
 source "https://rubygems.org"
 
 gem "rake"
-gem "rake-compiler"
 
 gemspec

Gemfile.lock

@@ -7,13 +7,10 @@ GEM
   remote: https://rubygems.org/
   specs:
     rake (10.4.2)
-    rake-compiler (0.9.5)
-      rake
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
   rake
-  rake-compiler
   version_sorter!

Rakefile

@@ -1,5 +1,4 @@
 require 'rake/testtask'
-require 'rake/extensiontask'
 
 task :default => :test
 
@@ -8,5 +7,14 @@ Rake::TestTask.new(:test) do |t|
   t.test_files = FileList['test/*test.rb']
 end
 
-Rake::ExtensionTask.new('version_sorter')
+file 'lib/version_sorter.bundle' => FileList['ext/version_sorter/*.{c,h,rb}'] do |task|
+  Dir.chdir 'ext/version_sorter' do
+    sh 'ruby extconf.rb'
+    sh 'make'
+  end
+  mv 'ext/version_sorter/version_sorter.bundle', task.name
+end
+
+desc "Compile the native extension"
+task :compile => 'lib/version_sorter.bundle'
 task :test => :compile