Initial commit ISBN

# Spice 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?**
Displays the book title, author, publisher, year of publication, and a small picture of the book cover for a query ISBN.

**What problem does your instant answer solve (Why is it better than organic links)?**
See book details without opening the Amazon page or Google Books page, for example.

**What is the data source for your instant answer? (Provide a link if possible)**
https://openlibrary.org/

**Why did you choose this data source?**
Free and open, unlimited API requests, reliable, large catalog.

**Are there any other alternative (better) data sources?**
Google Books and read.gov maybe, but these have daily limits on API requests.

**What are some example queries that trigger this instant answer?**
"isbn 0451526538", "isbn number 0451526538", "0451526538 isbn", "0451526538 isbn number"

**Which communities will this instant answer be especially useful for? (gamers, book lovers, etc)**
Book lovers!

**Is this instant answer connected to a DuckDuckHack [instant answer idea](https://duck.co/ideas)?**
Yes, this – https://duck.co/ideas/idea/301/isbn-barcode-lookup

**Which existing instant answers will this one supersede/overlap with?**
None. Searches for "isbn xxxxxxxxxxxxx" and "isbn number xxxxxxxxxxxxx" did not return instant answers.

**Are you having any problems? Do you need our help with anything?**
Yes, please! Testing on mobile and placing css styles in another file rather than inline in the handlebar. Would also appreciate suggestions to improve on the instant answer appearance!

**\*\*Note:** Please attach a screenshot for new instant answer pull requests, and for pull requests which modify the look/design of existing instant answers.
![solong](https://cloud.githubusercontent.com/assets/6028224/3281332/da8e3054-f4a1-11e3-9a40-2530cf6bd28b.png)
![fahreheit451](https://cloud.githubusercontent.com/assets/6028224/3281333/e178bc4a-f4a1-11e3-84f0-67ae1932de61.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
        [] Google Chrome   
        [X] Firefox         
        [] Opera           
        [] Safari          

    - iOS (iPhone)
        [] Safari Mobile   
        [] Google Chrome   
        [] Opera           

    - iOS (iPad)
        [] Safari Mobile   
        [] Google Chrome   
        [] Opera            

    - Android
        [] Firefox         
        [] Native Browser  
        [] Google Chrome   
        [] Opera

     -  [X] Firefox – Debian
```

Check if `api_result` exists, too, before accessing it. You can do:

```javascript
if (!api_result || api_result.error) {
   ...
}
```