mbleigh/acts-as-taggable-on — pull request #417 by rgould (2013-10-05 00:05:09+00:00)
Title: Let '.count' work when tagged_with is accompanied by a group clause

Give `group` a default of `[]`, which will later evaluate into a no-op by Rails. Previously this would be `nil`, which Rails translates to " AS " in SQL, generating an invalid statement.