'use strict'
'use strict'

missing 'use strict' causing problem for older version of node.

![screenshot from 2016-05-13 02 16 57](https://cloud.githubusercontent.com/assets/9411252/15229922/ce811080-18b0-11e6-9b29-32f33ad96511.png)

Closes #36

sindresorhus/anatine