astronomy picture of day

**What does your instant answer do?**
 Display astronomy picture of the day

**What problem does your instant answer solve (Why is it better than organic links)?**
 Saves a click

**What is the data source for your instant answer? (Provide a link if possible)**
 Nasa, http://apod.nasa.gov/apod/astropix.html

**Why did you choose this data source?**
 Using suggested source.

**Are there any other alternative (better) data sources?**
Might be.

**What are some example queries that trigger this instant answer?**
apod, astronomy picture of day

**Which communities will this instant answer be especially useful for? (gamers, book lovers, etc)**
 general users.

**Is this instant answer connected to a DuckDuckHack [instant answer idea](https://duck.co/ideas)?**
 Yes, [here](https://duck.co/ideas/idea/373/astronomy-picture-of-the-day)

**Which existing instant answers will this one supersede/overlap with?**
 No idea.

**Are you having any problems? Do you need our help with anything?**

![apod_1](https://cloud.githubusercontent.com/assets/1424236/3142205/78039b28-e9b0-11e3-965a-b62820dea163.png)
![apod_2](https://cloud.githubusercontent.com/assets/1424236/3142207/7d5101f6-e9b0-11e3-8fab-7bcba85af075.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://github.com/duckduckgo/duckduckgo-documentation/blob/master/duckduckhack/styleguides/design_styleguide.md)
[X] Tested cross-browser compatability

    Please let us know which browsers/devices you've tested on:
      - Mac OSX
        [X] Google Chrome   
        [X] Firefox         
```
@killerfish I looked into it, and we can't support quotes in the backend (but we can on DuckPAN because it does this https://github.com/duckduckgo/p5-app-duckpan/blob/master/lib/App/DuckPAN/Web.pm#L159...L161. I can see why that's confusing.)