Moved Shadow DOM tests to a separate folder

Since we need to import the library with different arguments, I decide to move
the tests into a model similar to the plugin and event driven webdriver tests.

Author: emanlove

Diff for: atest/acceptance/locators/piercing_shadowdom.robot renamed to atest/acceptance/3-shadow_dom/piercing_shadowdom.robot

@@ -1,7 +1,11 @@
 *** Settings ***
 Documentation     Tests different supported xpath strategies
+Library           SeleniumLibrary    shadowdom_piercing=True
+Resource          resource_shadowdom.robot
+Suite Setup       Open Browser    ${FRONT_PAGE}    ${BROWSER}    alias=shadowdom
+...                   remote_url=${REMOTE_URL}
+Suite Teardown    Close All Browsers
 Test Setup        Go To Page "shadow_dom.html"
-Resource          ../resource.robot
 
 *** Test Cases ***
 Multiple Locators with double arrows as separator should work

Diff for: atest/acceptance/3-shadow_dom/resource_shadowdom.robot

@@ -0,0 +1,7 @@
+*** Settings ***
+Resource    ../variables.robot
+
+*** Keywords ***
+Go To Page "${relative url}"
+    [Documentation]    Goes to page
+    Go To    ${ROOT}/${relative url}