FakeImg.pl placeholder image Snippet added

I recently discovered the great placeholder website [fakeimg.pl](http://fakeimg.pl/).

**tabTrigger** : `fakeimg`

This snippet tabs through all of the available options (and their `defaults`):

- horizontal size `350`
- vertical size `200`
- background color `00CED1` (darkturquoise)
- text color `FFF` (white)
- sample text `img+placeholder` (img placeholder)

FakeImg.pl also has support for `&font=lobster` and possibly other fonts though options are not documented on the site.

Below is a screenshot of the default settings.

![Screenshot of the default image](https://raw.github.com/tinacious/fakeimg.sublime-snippet/master/fakeimg-screenshot.png)