Flights by route Spice Instant Answer

**What does your Instant Answer do?**
Allows users to search for real-time flight information by airline, source city, and destination city (this IA returns flight information for a 24-hour window starting six hours before the current time).

**What problem does your Instant Answer solve (Why is it better than organic links)?**
Organic links do not generally show real-time information about flights, even if they do link to the appropriate pages.

**What is the data source for your Instant Answer? (Provide a link if possible)**
Flightstats (http://www.flightstats.com)
The airlines and cities data files were scraped using the Flightstats API; I also included the scraping script (written in Python) in the shared directory.

**Why did you choose this data source?**
This is the same service that DDG currently uses for its Airlines IA.

**Are there any other alternative (better) data sources?**
Not that I know of/tried.

**What are some example queries that trigger this Instant Answer?**
"Jetblue Boston to Los Angeles", "Aer Lingus Boston to Paris"

**Which communities will this Instant Answer be especially useful for? (gamers, book lovers, etc)**
Travelers

**Is this Instant Answer connected to a DuckDuckHack [Instant Answer idea](https://duck.co/ideas)?**
Yes--this IA was developed in response to https://duck.co/ideas/idea/3931/list-of-flights-and-status-by-location

**Which existing Instant Answers will this one supersede/overlap with?**
Complements the Airlines Spice IA, which returns information by flight code. Much of the code for this IA is based on the Airlines Spice.

**Are you having any problems? Do you need our help with anything?**
No problems on my end, but I would appreciate all comments and feedback on how to make the answer run more efficiently on your servers, given the large trigger list (as well as any code improvements/suggestions in general!). Also, it would be great to know if it is possible to insert a regex  into the spice test file (I could not find a way to do it, but left a comment about what such a test might look like).

**What are the terms of use for the API? Will DuckDuckGo need specific authorization (e.g. an API key)? Are there any costs associated with API usage?**
Yes; DDG should already have an API app ID and key with FlightStats because of the Airlines Spice.

**What does the Instant Answer look like? (Provide a screenshot for new or updated Instant Answers)**
![screen shot 2014-10-22 at 2 41 51 am](https://cloud.githubusercontent.com/assets/5326740/4732215/def23e34-59b8-11e4-90f6-7564eeeaa8c9.png)
![screen shot 2014-10-22 at 2 42 22 am](https://cloud.githubusercontent.com/assets/5326740/4732216/e1248e1e-59b8-11e4-9820-9ec119671d36.png)


## Checklist
Please place an 'X' where appropriate.

```
[X] Added metadata and attribution information
[X] Wrote test file and added to t/ directory
[X] Verified that instant answer adheres to design guidelines (https://duck.co/duckduckhack/design_styleguide)
[X] Verified that instant answer adheres to code styleguide (https://duck.co/duckduckhack/code_styleguide)
[] Tested cross-browser compatibility

    Please let us know which browsers/devices you've tested on:
    - Windows 8
        [] Google Chrome
        [] Firefox
        [] Opera
        [] IE 10

    - Windows 7
        [] Google Chrome
        [] Firefox
        [] Opera
        [] IE 8
        [] IE 9
        [] IE 10

    - Windows XP
        [] IE 7
        [] IE 8

    - Mac OSX
        [] Google Chrome
        [X] Firefox
        [] Opera
        [X] Safari

    - iOS (iPhone)
        [] Safari Mobile
        [] Google Chrome
        [] Opera

    - iOS (iPad)
        [] Safari Mobile
        [] Google Chrome
        [] Opera

    - Android
        [] Firefox
        [] Native Browser
        [] Google Chrome
        [] Opera
```

would bump this above the first return:

```perl
return unless @flightcodes;
return ( ... );
```