Autoload rules from config Fixes grunt-coffeelint#51

I created a gist that can be checked out and run to demonstrate the issue this solves.

https://gist.github.com/AsaAyers/140023f09a10c2d0a149

Without this change in place `coffeelint Gruntfile.coffee` will report the missing `use strict` and `grunt` will report all is fine. The correct output should look like this

```
➜  140023f09a10c2d0a149 git:(master) ✗ npm test

> gcl-test@0.0.0 test /tmp/140023f09a10c2d0a149
> coffeelint Gruntfile.coffee; grunt

resolve /tmp/140023f09a10c2d0a149
  ✗ Gruntfile.coffee
     ✗ #4: Missing 'use strict' statement.

✗ Lint! » 1 error and 0 warnings in 1 file

Running "coffeelint:tests" (coffeelint) task
resolve /tmp/140023f09a10c2d0a149

Gruntfile.coffee
  ✖  line 4  Missing 'use strict' statement

✖ 1 error

Warning: Task "coffeelint:tests" failed. Use --force to continue.

Aborted due to warnings.
npm ERR! Test failed.  See above for more details.
npm ERR! not ok code 0
```