Fix count method to work with select statement for Rails 4.1

Changes in Rails 4.1 prevents .count from working when you do something like ```User.select("id, name").count``` which would generate the SQL: ```SELECT COUNT(id, name) FROM users;``` which gives an error.

One work around I found was instead calling ```User.select("id, name").count(:all)``` which generates the SQL ```SELECT COUNT(*) FROM users;``` which works.