jprichardson/string.js — pull request #95 by JordanAdams (2014-07-23 13:04:32+00:00)
Title: Added replaceAt() method

Replaces the character at the given index with the replacement.

**Example:**
```javascript
var string = "abc_123";
var output = S(string).replaceAt(3, ":"); // abc:123
```