Bug 951654 - Fix unable to locate element box0 intermittently. r=automatedtester

Set search timeout to 30 seconds so that box0 could have enough time to
appear. The original timeout 3 seconds might be too short when try
servers have heavy loading.

testing/marionette/client/marionette/tests/unit/test_implicit_waits.py

@@ -10,7 +10,7 @@ class TestImplicitWaits(MarionetteTestCase):
         test_html = self.marionette.absolute_url("test_dynamic.html")
         self.marionette.navigate(test_html)
         add = self.marionette.find_element("id", "adder")
-        self.marionette.set_search_timeout("3000")
+        self.marionette.set_search_timeout("30000")
         add.click()
         # All is well if this doesnt throw
         self.marionette.find_element("id", "box0")