Add a spec task to the Rakefile.

Rakefile

@@ -39,19 +39,11 @@ task :release => [:gem, :package] do
   end
 end
 
-task :test => [:markdown_span_tests, :markdown_block_tests]
+begin
+  require 'spec/rake/spectask'
 
-task :markdown_block_tests do
-	tests = Dir['tests/unittest/**/*.md'].join(' ')
-	puts "Executing tests #{tests}"
-#	ok = marutest(tests)
-	ok = system "ruby -Ilib bin/marutest #{tests}"
-	raise "Failed block unittest" if not ok
-end
-
-task :markdown_span_tests do
-	ok = system( "ruby -Ilib lib/maruku/tests/new_parser.rb v b")
-	raise "Failed span unittest" if not ok
+  Spec::Rake::SpecTask.new
+rescue LoadError => e
 end
 
 require 'rake/rdoctask'