Add feature test for plugin get command

Author: ernilambar

features/plugin-get.feature

@@ -0,0 +1,47 @@
+Feature: Get WordPress plugin
+
+  Scenario: Get plugin info
+    Given a WP install
+    And a wp-content/plugins/foo.php file:
+      """
+      /**
+       * Plugin Name: Sample Plugin
+       * Description: Description for sample plugin.
+       * Requires at least: 6.0
+       * Requires PHP: 5.6
+       * Version: 1.0.0
+       * Author: John Doe
+       * Author URI: https://example.com/
+       * License: GPLv2 or later
+       * License URI: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+       * Text Domain: sample-plugin
+       */
+       """
+
+    When I run `wp plugin get foo --fields=name,author,version,status`
+    Then STDOUT should be a table containing rows:
+      | Field   | Value    |
+      | name    | foo      |
+      | author  | John Doe |
+      | version | 1.0.0    |
+      | status  | inactive |
+
+  @require-wp-6.5
+  Scenario: Get Requires Plugins header of plugin
+    Given a WP install
+    And a wp-content/plugins/foo.php file:
+      """
+      <?php
+      /**
+       * Plugin Name: Foo
+       * Description: Foo plugin
+       * Author: John Doe
+       * Requires Plugins: jetpack, woocommerce
+       */
+       """
+
+    When I run `wp plugin get foo --field=requires_plugins`
+    Then STDOUT should be:
+      """
+      jetpack, woocommerce
+      """