Internal: Add behat tests

tests/behat/features/actionUserLogin.feature

@@ -0,0 +1,16 @@
+Feature: Login user
+
+  Scenario: Login as admin user successfully
+    Given I am on "/login"
+    Then I should see "Sign in"
+    And I fill in "admin" for "login"
+    And I fill in "admin" for "password"
+    Then I press "Login"
+    Then wait for the page to be loaded
+    Then I should see "My courses"
+    Then I should not see an error
+
+  Scenario: Login as admin
+    Given I am a platform administrator
+    Then I should not see an error
+    Then I should see "My courses"

tests/behat/features/adminFillUsers.feature

@@ -1,13 +1,5 @@
 Feature: Fill users
 
-  Scenario: Login as admin user successfully
-    Given I am on "/login"
-    Then I should see "Sign in"
-    And I fill in "admin" for "login"
-    And I fill in "admin" for "password"
-    Then I press "Login"
-    Then I should not see an error
-
   Scenario: Create tests users successfully
     Given I am a platform administrator
     Then I am on "/main/admin/filler.php?fill=users"