title: Composer installs TCPDF with .git repository
body: <p>I am trying to install TCPDF via composer.
  It works, but unfortunately, it always installs also whole .git directory which has 93 MB.
  I only want to install TCPDF files without .git stuff.</p>
  
  <p>How to do that?</p>
  
  <p>Here's my composer.json:</p>
  
  <pre><code>{
      "name": "myprojects/project1",
      "require": {
          "yiisoft/yii": "~1.1.15",
          "twbs/bootstrap": "~3.2.0",
          "tecnick.com/tcpdf": "~6.0.89",
          "phpoffice/phpexcel": "~1.8.0"
      }
  }
  </code></pre>
  
  <p>Thank you in advance.</p>
  
  <p><strong>EDIT 1:</strong></p>
  
  <p>Following is the composer configuration in the TCPDF composer file downloaded from packagist repo - not sure if this might help solving the issue:</p>
  
  <pre><code>{
      "name": "tecnick.com/tcpdf",
      "version": "6.0.089",
      "homepage": "http://www.tcpdf.org/",
      "type": "library",
      "description": "TCPDF is a PHP class for generating PDF documents.",
      "keywords": ["PDF","tcpdf","PDFD32000-2008","qrcode","datamatrix","pdf417","barcodes"],
      "license": "LGPLv3",
      "authors": [
      {
          "name": "Nicola Asuni",
          "email": "info@tecnick.com",
          "homepage": "http://nicolaasuni.tecnick.com"
      }
      ],
      "require": {
          "php": "&gt;=5.3.0"
      },
      "autoload": {
          "classmap": [
          "fonts",
          "config",
          "include",
          "tcpdf.php",
          "tcpdf_parser.php",
          "tcpdf_import.php",
          "tcpdf_barcodes_1d.php",
          "tcpdf_barcodes_2d.php",
          "include/tcpdf_colors.php",
          "include/tcpdf_filters.php",
          "include/tcpdf_font_data.php",
          "include/tcpdf_fonts.php",
          "include/tcpdf_images.php",
          "include/tcpdf_static.php",
          "include/barcodes/datamatrix.php",
          "include/barcodes/pdf417.php",
          "include/barcodes/qrcode.php"
          ]
      }
  }
  </code></pre>
  
  <p><strong>EDIT 2:</strong></p>
  
  <p>I have changed composer config as follows by adding config option "preferred-install" : "dist", but did not help. I also tried "dev-master", still the same... :-(</p>
  
  <pre><code>{
      "name": "myprojects/project1",
      "config": {
          "preferred-install" : "dist"
      },
      "require": {
          "yiisoft/yii": "~1.1.15",
          "twbs/bootstrap": "~3.2.0",
          "tecnick.com/tcpdf": "~6.0@stable",
          "phpoffice/phpexcel": "~1.8.0"
      }
  }
  </code></pre>