Add ignore option

To ignore models, use the --ignore (-I) argument:
php artisan ide-helper:models --ignore="Admin\Model"
php artisan ide-helper:models -I Post,User
Fixes #35

src/Barryvdh/LaravelIdeHelper/ModelsCommand.php

@@ -58,6 +58,7 @@ class ModelsCommand extends Command {
         $this->write = $this->option('write');
         $this->dir = $this->option('dir');
         $model = $this->argument('model');
+        $ignore = $this->option('ignore');
         $this->reset = $this->option('reset');
 
         //If filename is default and Write is not specified, ask what to do
@@ -67,7 +68,7 @@ class ModelsCommand extends Command {
             }
         }
 
-        $content = $this->generateDocs($model);
+        $content = $this->generateDocs($model, $ignore);
 
         if(!$this->write){
             $written = \File::put($filename, $content);
@@ -89,7 +90,6 @@ class ModelsCommand extends Command {
     {
         return array(
             array('model', InputArgument::OPTIONAL, 'Which models to include', '*'),
-            array('ignore', InputArgument::OPTIONAL, 'Which models to ignore', null),
         );
     }
 
@@ -106,10 +106,11 @@ class ModelsCommand extends Command {
             array('write', 'W', InputOption::VALUE_NONE, 'Write to Model file'),
             array('nowrite', 'N', InputOption::VALUE_NONE, 'Don\'t write to Model file'),
             array('reset', 'R', InputOption::VALUE_NONE, 'Remove the original phpdocs instead of appending'),
+            array('ignore', 'I', InputOption::VALUE_OPTIONAL, 'Which models to ignore', ''),
         );
     }
 
-    protected function generateDocs($model){
+    protected function generateDocs($model, $ignore = ''){
 
 
         $output = "<?php
@@ -128,8 +129,15 @@ class ModelsCommand extends Command {
             $models = explode(',', $model);
         }
 
-        foreach($models as $name){
+        $ignore = explode(',', $ignore);
 
+        foreach($models as $name){
+            if(in_array($name, $ignore)){
+                $this->comment("Ignoring model '$name'");
+                continue;
+            }else{
+                $this->comment("Loading model '$name'");
+            }
             $this->properties = array();
             $this->methods = array();
             if(class_exists($name)){