Make behave grafana test more resilient

Apparently firefox geckodriver renders the grafana home page in a different
order than chromedriver. So we wait for an element which gets rendered at the
very end.

Closes: #463

test/behave/features/grafana.feature

@@ -6,12 +6,15 @@ Feature: Test grafana admin login
 Scenario: Open grafana
   When I open the grafana URL
   Then I wait on element "//input[@name='user']" for 25000ms to be visible
+  And I expect that the title is "Grafana"
   And I expect that element "#inputPassword" is visible
+  And I expect that the path is "/login"
 
 Scenario: Login to grafana
   Given the element "//input[@name='user']" is visible
   When I enter the "grafana" "username" in the inputfield "//input[@name='user']"
   And I enter the "grafana" "password" in the inputfield "#inputPassword"
   And I click on the button "//div[@id='login-view']//button[@type='submit']"
-  Then I wait on element "/html/body/grafana-app/sidemenu/a" for 25000ms to be visible
+  Then I wait on element "/html/body/grafana-app/div/div/div/react-container/div/div[2]/div/div[1]/div/div/div[2]/div/div/div[1]/div/div[2]/div" for 25000ms to be visible
+  And I expect that the path is "/"
   And I expect that the title is "Home - Grafana"