Add search index excluded post

Post to test `search: false`

test/_posts/2017-11-28-post-exclude-search.md

@@ -0,0 +1,12 @@
+---
+title:  "Exclude Post from Search Index"
+search: false
+categories: 
+  - Jekyll
+---
+
+This post should not appear in the search index because it has the following YAML Front Matter:
+
+```yaml
+search: false
+```