Royal mail IA

Note: Parcelforce is a sub-company of Royal Mail so their tracking codes can be used on both sites, but they are more in-depth on the correct website.

**What does your instant answer do?**
Link to tracking services available for Royal Mail / Parcelforce parcels.

**What is the data source for your instant answer? (Provide a link if possible)**
The regex is based on the information provided on this page: http://www.parcelforce.com/help-information/frequently-asked-questions/track-parcel#2

**Why did you choose this data source?**
I chose it because it is official.

**Are there any other alternative (better) data sources?**
I couldn't find any free ones.

**What are some example queries that trigger this instant answer?**
royal mail RU401513974GB

**Which communities will this instant answer be especially useful for? (gamers, book lovers, etc)**
Merchants

**Is this instant answer connected to a DuckDuckHack [instant answer idea](https://duck.co/ideas)?**
Yes, https://duck.co/ideas/idea/491/royal-mail-tracking

**Which existing instant answers will this one supercede/overlap with?**
None I am aware of at the moment.

![ddg royal mail](https://cloud.githubusercontent.com/assets/2399307/2532043/8cf583ca-b53a-11e3-973e-b2d779b15ee1.png)

##Checklist
```
[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:
    - Ubuntu
        [X] Google Chrome
        [X] Firefox
        [] Opera
```