Fix group search to check path as well as name.

The API documentation says:

"You can search for groups by name or path with: /groups?search=Rails"

But you can't because the search query only checks the name, not
the path. This fixes that.

app/models/group.rb

@@ -91,7 +91,7 @@ class Group < Namespace
 
   class << self
     def search(query)
-      where("LOWER(namespaces.name) LIKE :query", query: "%#{query.downcase}%")
+      where("LOWER(namespaces.name) LIKE :query or LOWER(namespaces.path) LIKE :query", query: "%#{query.downcase}%")
     end
 
     def sort(method)