Enable screenshot comparison in external build

This change actually enabled the screenshot comparison in the
visual regression tests. We used Docker to provision Chrome
and ChromeDriver to eliminate the discrepancy of environment
between local development and Travis CI.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=237811918

javatests/google/registry/webdriver/WebDriverRule.java

@@ -66,7 +66,7 @@ public final class WebDriverRule extends ExternalResource
   private static final Dimension DEFAULT_WINDOW_SIZE = new Dimension(1200, 2000);
 
   private static final String GOLDENS_PATH =
-      getResource(WebDriverRule.class, "scuba_goldens/chrome-linux").getFile();
+      getResource(WebDriverRule.class, "goldens/chrome-linux").getFile();
 
   private WebDriver driver;
   private WebDriverPlusScreenDiffer webDriverPlusScreenDiffer;
@@ -99,10 +99,10 @@ public final class WebDriverRule extends ExternalResource
 
   @Override
   protected void after() {
-    webDriverPlusScreenDiffer.verifyAndQuit();
     try {
-      driver.quit();
+      webDriverPlusScreenDiffer.verifyAndQuit();
     } finally {
+      driver.quit();
       driver = null;
     }
   }