Node version: 5.6.0

ShellJS version (the most recent version/Github branch you see the bug on): 0.6.0

Operating system: OS X 10.11.4

Description of the bug: Running phpcs through shelljs is incredibly slow. Directly through shell, running phpcs on an empty php file takes 16ms. Running through shelljs the same command takes 59s.

Example ShellJS command to reproduce the error:

var shell = require('shelljs');

shell.exec('phpcs --report=json --standard=PSR2 -n ./test/test.php');
console.log(shell.stdout);