Fix #269 - Use Ruby major and minor versions to load extension, but n…

…ot the patch level.

Rakefile

@@ -38,7 +38,7 @@ Rake::ExtensionTask.new do |ext|
   ext.gem_spec = default_spec
   ext.name = SO_NAME
   ext.ext_dir = "ext/#{SO_NAME}"
-  ext.lib_dir = "lib/#{RUBY_VERSION}"
+  ext.lib_dir = "lib/#{Gem::Version.new(RUBY_VERSION).segments[0..1].join('.')}"
   ext.cross_compile = true
   ext.cross_platform = ['x86-mingw32', 'x64-mingw32']
 end

lib/ruby-prof.rb

@@ -1,9 +1,10 @@
 # encoding: utf-8
+require 'rubygems/version'
 
 # Load the C-based binding.
 begin
-  RUBY_VERSION =~ /(\d+\.\d+\.\d+)/
-  require "#{$1}/ruby_prof.so"
+  version = Gem::Version.new(RUBY_VERSION)
+  require "#{version.segments[0..1].join('.')}/ruby_prof.so"
 rescue LoadError
   require "ruby_prof.so"
 end