Update test

Author: aguspe

rb/spec/integration/selenium/webdriver/child_process_spec.rb renamed to rb/spec/unit/selenium/webdriver/common/child_process_spec.rb

@@ -17,7 +17,7 @@
 # specific language governing permissions and limitations
 # under the License.
 
-require_relative 'spec_helper'
+require File.expand_path('../spec_helper', __dir__)
 
 module Selenium
   module WebDriver