Fix problem with admin test - cleaning database

Signed-off-by: Marcin Woźniak <y0rune@aol.com>

buisnesslogic/src/test/java/com/plannaplan/services/UserServiceTest.java

@@ -2,6 +2,8 @@ package com.plannaplan.services;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.annotation.DirtiesContext.MethodMode;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringRunner;
 
@@ -108,10 +110,9 @@ public class UserServiceTest {
         assertTrue(userService.adminExists());
     }
     
+    
     @Test
-    /**
-     * In future can fail the test due to create a admin user in the another tests.
-     */
+    @DirtiesContext(methodMode = MethodMode.BEFORE_METHOD)
      public void shouldReturnNotAdminExists() {
         final String email = "shouldReturnNotAdminExists@UserService.test";
         this.userService.save(new User("StudentTom", "Smieszny", email, UserRoles.STUDENT));