fix imports

spring-security-custom-permission/src/test/java/org/baeldung/web/CustomUserDetailsServiceTest.java

@@ -9,6 +9,7 @@ import org.baeldung.persistence.dao.UserRepository;
 import org.baeldung.persistence.model.User;
 import org.junit.Test;
 import org.junit.runner.RunWith;
+import org.junit.After;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.SpringApplicationConfiguration;
 import org.springframework.security.authentication.AuthenticationProvider;