Added goodie to convert alphabetic phone number to numeric phone number.

# Goodie Pull Request Template

Using this template will help us better understand your Instant Answer and assist you when necessary.  Simply copy and paste the markdown below into the description of your GitHub pull request and complete as appropriate.

**What does your Instant Answer do?**
Converts alphabetic phone numbers to numeric phone numbers. (E.g., Query: '1-800-fun-hack to phone number' returns 'Phone Number: 1-800-386-4225'

**What problem does your Instant Answer solve (Why is it better than organic links)?**
Right now organic results don't convert the alphabetic phone numbers into easy to dial numeric phone numbers.

**What is the data source for your Instant Answer? (Provide a link if possible)**
Mapped phone keys between numbers and the alphabet.

**Why did you choose this data source?**
Its the definitive source

**Are there any other alternative (better) data sources?**
None that I'm aware of.

**What are some example queries that trigger this Instant Answer?**
1-800-LAWYR-UP to digits
1-800-fun-hack to phone number

**Which communities will this Instant Answer be especially useful for? (gamers, book lovers, etc)**
Users in the United States that don't want to think about converting phone numbers with words / letters into an actual phone number.

**Is this Instant Answer connected to a DuckDuckHack [Instant Answer idea](https://duck.co/ideas)?**
Yes, https://duck.co/ideas/idea/4718/letters-to-keypad-numbers-and-vice-versa

**Which existing Instant Answers will this one supercede/overlap with?**


**Are you having any problems? Do you need our help with anything?**
I've only completed the first part, going from alphabetic phone numbers to numeric phone numbers, not going from numeric phone numbers to words.

**Where did you hear about DuckDuckHack? (For first time contributors)**
Blog entry, http://blog.ackx.net/duckduckhack-accepted.html.

**What does the Instant Answer look like? (Provide a screenshot for new or updated Instant Answers)**
![image](https://cloud.githubusercontent.com/assets/886585/5466339/c5eb24b4-856e-11e4-9ec6-daf7fdccbbdb.png)
http://i.imgur.com/dbRbKDo.png

## Checklist
Please place an 'X' where appropriate.

```
[X] Added metadata and attribution information (https://duck.co/duckduckhack/metadata)
[X] Wrote test file and added to t/ directory (https://duck.co/duckduckhack/goodie_tests)
[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)
[X] Tested cross-browser compatibility

    Please let us know which browsers/devices you've tested on:
    - Windows 8
        [X] Google Chrome
        [X] Firefox
        [] Opera
        [X] IE 10

    - Windows 7
        [X] Google Chrome
        [X] Firefox
        [] Opera
        [X] IE 8
        [X] IE 9
        [X] IE 10

    - Windows XP
        [] IE 7
        [X] IE 8

    - Mac OSX
        [] Google Chrome
        [] Firefox
        [] Opera
        [] Safari

    - iOS (iPhone)
        [] Safari Mobile
        [] Google Chrome
        [] Opera

    - iOS (iPad)
        [] Safari Mobile
        [] Google Chrome
        [] Opera

    - Android
        [] Firefox
        [] Native Browser
        [] Google Chrome
        [] Opera
```
Can you add some tests for things that shouldn't work, maybe once you've tightened up the inputs?