Support partial indexes.

amw · estolfo · commit 630db7bbdc3c · 2015-12-21T12:29:28.000+01:00
Partial indexes were added in MongoDB 3.2 and ruby driver 2.2.
diff --git a/lib/mongoid/indexable/validators/options.rb b/lib/mongoid/indexable/validators/options.rb
@@ -26,7 +26,8 @@ module Options
           :key,
           :sphere_version,
           :text_version,
-          :version
+          :version,
+          :partial_filter_expression
         ]
 
         VALID_TYPES = [
