Allow the running of Rails/Merb integration specs independently

Rakefile

@@ -105,15 +105,23 @@ end
 
 namespace :spec do
   desc "Run the integration specs"
-  task :integration do
-    Dir.chdir "spec/integration/rails" do
-      result = system "rake test:integration"
-      raise "Tests failed" unless result
+  task :integration => ["integration:rails", "integration:merb"]
+
+  namespace :integration do
+    desc "Run the Rails integration specs"
+    task :rails do
+      Dir.chdir "spec/integration/rails" do
+        result = system "rake test:integration"
+        raise "Tests failed" unless result
+      end
     end
 
-    Dir.chdir "spec/integration/merb" do
-      result = system "rake spec"
-      raise "Tests failed" unless result
+    desc "Run the Merb integration specs"
+    task :merb do
+      Dir.chdir "spec/integration/merb" do
+        result = system "rake spec"
+        raise "Tests failed" unless result
+      end
     end
   end
 end