Add Chinese Zodiac goodie

**What does your instant answer do?**
It returns the Chinese zodiac animal for a given year. 

**What problem does your instant answer solve (Why is it better than organic links)?**
Much easier than scanning down a list of years or re-inputting the year into an online calculator.

**What is the data source for your instant answer? (Provide a link if possible)**
N/A

**Why did you choose this data source?**
N/A

**Are there any other alternative (better) data sources?**
N/A

**What are some example queries that trigger this instant answer?**
'2004 chinese zodiac animal', 'what was the chinese zodiac animal in 1992', 'what will the chinese zodiac animal be for 2056'

**Which communities will this instant answer be especially useful for? (gamers, book lovers, etc)**
Expectant parents, getters-of-tattoos, Chinese astrologers.

**Is this instant answer connected to a DuckDuckHack [instant answer idea](https://duck.co/ideas)?**
Yes, [this one](https://duck.co/ideas/idea/755/chinese-zodiac-instant-answer). It looks like there was also a [previous attempt to implement this](https://github.com/duckduckgo/zeroclickinfo-goodies/pull/188) that didn't go anywhere.

**Which existing instant answers will this one supercede/overlap with?**
Possibly the proposed [Zodiac goodie](https://github.com/duckduckgo/zeroclickinfo-goodies/pull/440/commits); both could potentially be triggered by a query ending in the words 'chinese zodiac'.

**Are you having any problems? Do you need our help with anything?**
Any advice would be welcome!

**\*\*Note:** Please attach a screenshot for new instant answer pull requests, and for pull requests which modify the look/design of existing instant answers.

![image](https://cloud.githubusercontent.com/assets/726198/3210624/7579bd4a-eed5-11e3-81bd-14dac188cafa.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:
    - 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
        [X] 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
```
It seems like some people might leave the year out while trying to get information on this year.  `what is the chinese zodiac animal`

Might also be cool to allow for a couple relative year inputs, specifically "last", "this" and "next". Anything beyond that, I think they can type out the 4 digits. :grin: