Assuming path to PHP on Linux.

[bweston92]

Instead of assuming PHP is always at /usr/bin/php we should check the path to see where PHP is. Linux has a good tool which we can find at /usr/bin/env. If we pass php to this it be more portable.

Diff:

-#!/usr/bin/php
+#!/usr/bin/env php
 <?php

 use Smacme\Commit\EmojiList;