Fixed sql injection vulneralbilities, changed header

## Description and Impact
Makes it pretty much ready for production, 

## URLs
> Links to bug tickets or user stories.

#### Risk Level:
- [X] Low
- [ ] Medium
- [ ] High

I would sanitize order like this:

```ruby
order = ["ASC","DESC"].detect{|order_type| order_type == order.upcase } || "ASC"
```
then instead of using conditionals for the order you can do it like this:

```ruby
closed_since(timespan).order("closed_at ?", order)
```
and the same for open_since