Implement target recipe keyword feature

features/cli/target.feature

@@ -0,0 +1,12 @@
+Feature: target recipe keyword
+
+  Scenario: registers the target host on which tasks should be evaluated
+    Given a recipe with:
+      """
+      target 'some_host.example'
+
+      puts env.target
+      """
+    When I execute the recipe
+    Then the exit status must be 0
+    And the output must contain exactly "some_host.example\n"