tsukasaoishi/fresh_connection — pull request #5 by tsukasaoishi (2014-09-29 14:36:41+00:00)
Title: pluck method throws exception when result of conditions is empty

For example

```ruby
User.limit(1).pluck(:name) #=> ["tsukasa"]
User.limit(0).pluck(:name) #=> NoMethodError: undefined method `keys' for nil:NilClass
```

result must be empty array.