Add feature specs for search

* Search by event name
* Search results exclude closed events
You can set up FactoryGirl traits to allow `event = create(:event, :closed)` and `create(:event, :open)`

```ruby
FactoryGirl.define do
  factory :event do
    # etc
    trait :closed do
      closing_date { 1.day.ago }
    end

    trait :open do
      closing_date { 1.day.from_now }
    end
end
```