Bttf todayinhistory

**What does your instant answer do?**
 Lists historical events on current/given day.

**What problem does your instant answer solve (Why is it better than organic links)?**
  Instant relevant information displayed.

**What is the data source for your instant answer? (Provide a link if possible)**
 Wikipedia.

**Why did you choose this data source?**
 Biggest online encyclopedia, regular updates etc.

**Are there any other alternative (better) data sources?**
 History.com could be considered, although its a matter of preference.

**What are some example queries that trigger this instant answer?**
 today in history, this day in history.

**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, https://duck.co/ideas/idea/482/today-in-history

**Which existing instant answers will this one supersede/overlap with?**
 No idea.

**Are you having any problems? Do you need our help with anything?**

##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         
```
@jagtalon @killerfish Apologies, we should make it more apparent, but it is covered in the FAQ:
https://duck.co/duckduckhack/faq#can-i-use-an-api-that-returns-xml