Create factory for plugins that resources can be registered with.

Tests/PHPCI/Plugin/Util/ExamplePlugins.php

@@ -0,0 +1,57 @@
+<?php
+namespace PHPCI\Plugin\Tests\Util;
+
+use PHPCI\Builder;
+use PHPCI\Model\Build;
+use PHPCI\Plugin;
+
+class ExamplePluginWithNoConstructorArgs {
+
+}
+
+class ExamplePluginWithSingleOptionalArg {
+    function __construct($optional = null)
+    {
+
+    }
+}
+
+class ExamplePluginWithSingleRequiredArg {
+
+    public $RequiredArgument;
+
+    function __construct($requiredArgument)
+    {
+        $this->RequiredArgument = $requiredArgument;
+    }
+}
+
+class ExamplePluginWithSingleTypedRequiredArg {
+
+    public $RequiredArgument;
+
+    function __construct(\stdClass $requiredArgument)
+    {
+        $this->RequiredArgument = $requiredArgument;
+    }
+}
+
+class ExamplePluginFull implements Plugin {
+
+    public $Options;
+
+    public function __construct(
+        Builder $phpci,
+        Build $build,
+        array $options = array()
+    )
+    {
+        $this->Options = $options;
+    }
+
+    public function execute()
+    {
+
+    }
+
+}