Merged in feature/from-pantheon (pull request #16)

code from pantheon

* code from pantheon

wp/wp-content/plugins/woocommerce/lib/packages/Psr/Container/ContainerExceptionInterface.php

@@ -0,0 +1,12 @@
+<?php
+
+namespace Automattic\WooCommerce\Vendor\Psr\Container;
+
+use Throwable;
+
+/**
+ * Base interface representing a generic exception in a container.
+ */
+interface ContainerExceptionInterface extends Throwable
+{
+}