Fix partial test

test/test_sass.rb

@@ -107,11 +107,16 @@ CSS
 
   context "importing partials" do
     setup do
-      content = ""
+      @site = Jekyll::Site.new(Jekyll.configuration({
+        "source" => source_dir,
+        "destination" => dest_dir
+      }))
+      @site.process
+      @test_css_file = dest_dir("css/main.css")
     end
 
-    should "import SCSS" do
+    should "import SCSS partial" do
-      assert_equal ".half { width: 30%; }", content
+      assert_equal ".half {\n  width: 50%; }\n", File.read(@test_css_file)
     end
   end
 end