Make the selenium driver for chrome available.
```
Unable to find the chromedriver executable. Please download the server from http://chromedriver.storage.googleapis.com/index.html and place it somewhere on your PATH. More info at https://github.com/SeleniumHQ/selenium/wiki/ChromeDriver. (Selenium::WebDriver::Error::WebDriverError)
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/selenium-webdriver-2.48.0/lib/selenium/webdriver/chrome/service.rb:37:in `executable_path'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/selenium-webdriver-2.48.0/lib/selenium/webdriver/chrome/service.rb:50:in `default_service'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/selenium-webdriver-2.48.0/lib/selenium/webdriver/chrome/bridge.rb:33:in `initialize'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/selenium-webdriver-2.48.0/lib/selenium/webdriver/common/driver.rb:60:in `new'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/selenium-webdriver-2.48.0/lib/selenium/webdriver/common/driver.rb:60:in `for'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/selenium-webdriver-2.48.0/lib/selenium/webdriver.rb:86:in `for'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/watir-webdriver-0.9.0/lib/watir-webdriver/browser.rb:46:in `initialize'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/mediawiki_selenium-1.5.0/lib/mediawiki_selenium/browser_factory/base.rb:226:in `new'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/mediawiki_selenium-1.5.0/lib/mediawiki_selenium/browser_factory/base.rb:226:in `new_browser'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/mediawiki_selenium-1.5.0/lib/mediawiki_selenium/browser_factory/base.rb:186:in `new_browser_for'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/mediawiki_selenium-1.5.0/lib/mediawiki_selenium/browser_factory/base.rb:140:in `browser_for'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/mediawiki_selenium-1.5.0/lib/mediawiki_selenium/environment.rb:157:in `browser'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/mediawiki_selenium-1.5.0/lib/mediawiki_selenium/support/modules/headless_helper.rb:71:in `browser'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/mediawiki_selenium-1.5.0/lib/mediawiki_selenium/page_factory.rb:25:in `on_page'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/page-object-1.1.0/lib/page-object/page_factory.rb:53:in `visit_page'
/mnt/jenkins-workspace/workspace/browsertests-Wikidata-WikidataTests-linux-chrome-sauce/tests/browser/features/step_definitions/entity_steps.rb:42:in `block in <top (required)>'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:48:in `instance_exec'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:48:in `block in cucumber_instance_exec'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:69:in `cucumber_run_with_backtrace_filtering'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:36:in `cucumber_instance_exec'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/rb_support/rb_step_definition.rb:97:in `invoke'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/step_match.rb:25:in `invoke'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/runtime/support_code.rb:60:in `invoke'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/rb_support/rb_world.rb:52:in `step'
/mnt/jenkins-workspace/workspace/browsertests-Wikidata-WikidataTests-linux-chrome-sauce/tests/browser/features/step_definitions/entity_steps.rb:23:in `block in <top (required)>'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:48:in `instance_exec'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:48:in `block in cucumber_instance_exec'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:69:in `cucumber_run_with_backtrace_filtering'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:36:in `cucumber_instance_exec'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/rb_support/rb_step_definition.rb:97:in `invoke'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/step_match.rb:25:in `invoke'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/runtime/support_code.rb:60:in `invoke'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/rb_support/rb_world.rb:52:in `step'
/mnt/jenkins-workspace/workspace/browsertests-Wikidata-WikidataTests-linux-chrome-sauce/tests/browser/features/step_definitions/entity_steps.rb:18:in `block in <top (required)>'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:48:in `instance_exec'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:48:in `block in cucumber_instance_exec'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:69:in `cucumber_run_with_backtrace_filtering'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/core_ext/instance_exec.rb:36:in `cucumber_instance_exec'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/rb_support/rb_step_definition.rb:97:in `invoke'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/step_match.rb:25:in `invoke'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/step_invocation.rb:60:in `invoke'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/step_invocation.rb:38:in `accept'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:106:in `block in visit_step'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:170:in `broadcast'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:105:in `visit_step'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/step_collection.rb:19:in `block in accept'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/step_collection.rb:18:in `each'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/step_collection.rb:18:in `accept'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:100:in `block in visit_steps'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:170:in `broadcast'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:99:in `visit_steps'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/background.rb:44:in `block in accept'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/background.rb:54:in `block in with_visitor'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/scenario.rb:79:in `with_visitor'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/background.rb:53:in `with_visitor'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/background.rb:41:in `accept'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:64:in `block in visit_background'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:170:in `broadcast'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:63:in `visit_background'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/feature.rb:36:in `accept'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:27:in `block in visit_feature'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:170:in `broadcast'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:26:in `visit_feature'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/features.rb:28:in `block in accept'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/features.rb:17:in `each'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/features.rb:17:in `each'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/features.rb:27:in `accept'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:21:in `block in visit_features'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:170:in `broadcast'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/ast/tree_walker.rb:20:in `visit_features'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/runtime.rb:49:in `run!'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/lib/cucumber/cli/main.rb:47:in `execute!'
/mnt/home/jenkins-deploy/.gem/2.0.0/gems/cucumber-1.3.20/bin/cucumber:13:in `<top (required)>'
/mnt/home/jenkins-deploy/.gem/2.0.0/bin/cucumber:23:in `load'
/mnt/home/jenkins-deploy/.gem/2.0.0/bin/cucumber:23:in `<main>'
features/aliases.feature:12:in `Given I am on an item page'
```