Add Logout scenario to tests

login_provider/test/behave/features/login.feature

@@ -18,3 +18,10 @@ Scenario: Login with a valid user
     And I click on the button "input#submit"
     Then I wait on element "input#password" for 1000ms to not exist
     And I expect that element "input#email" does not exist
+
+Scenario: Logout
+    Given the element "input#submit" is visible
+    And the element "input#submit" contains the text "Logout"
+    When I click on the element "input#submit"
+    Then I wait on element "input#email" for 1000ms to exist
+    And I expect that element "input#password" does exist