Remove obsolete files and directories

It should be clear that composer dependencies need to be installed
in order to work on and test the library, so the `bootstrap.php` 
file can be deleted.

Since USAGE.md has been merged into README.md, the `site` 
directory is not needed anymore.

Author: jeromegamez

Diff for: .gitignore

@@ -1,5 +1,4 @@
 .phpunit.result.cache
 composer.lock
 phpunit.xml
-site
 vendor

Diff for: phpunit.xml.dist

@@ -3,7 +3,7 @@
 <phpunit
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
-    bootstrap="tests/bootstrap.php"
+    colors="true"
 >
     <testsuites>
         <testsuite name="GeoJson Test Suite">

Diff for: tests/bootstrap.php

@@ -1,7 +0,0 @@
-<?php
-
-if (!file_exists($autoloadFile = __DIR__.'/../vendor/autoload.php')) {
-    throw new RuntimeException('Install dependencies to run test suite.');
-}
-
-require_once $autoloadFile;