Add test task

Rakefile

@@ -1,11 +1,20 @@
-require "bundler/gem_tasks"
+require 'bundler/gem_tasks'
+require 'rake/testtask'
 require 'rake/extensiontask'
 
 spec = Gem::Specification.load('memcached.gemspec')
 Rake::ExtensionTask.new('rlibmemcached', spec) do |ext|
-  ext.lib_dir = 'lib/memcached'
+  ext.lib_dir = 'lib'
 end
 
+Rake::TestTask.new do |t|
+  t.libs << 'lib' << 'test'
+  t.pattern = 'test/**/*_test.rb'
+  t.verbose = false
+  t.warning = true
+end
+task :default => [:compile, :test]
+
 task :swig do
   run("swig -DLIBMEMCACHED_WITH_SASL_SUPPORT -Iext/libmemcached-0.32 -ruby -autorename -o ext/rlibmemcached_wrap.c.in ext/rlibmemcached.i", "Running SWIG")
   swig_patches = {