Java 11 migrate 7 remaining f (#1115)

* Moves facade to Java 11

* Moves factory-kit to Java 11

* Moves factory-method to Java 11

* Moves feature-toggle to Java 11

* Moves fluentinterface to Java 11

* Moves flux to Java 11

* Moves flyweight to Java 11

* Moves front-controller to Java 11

* Uses stream properly

* Resolves issues with ci

feature-toggle/src/test/java/com/iluwatar/featuretoggle/user/UserGroupTest.java

@@ -23,34 +23,34 @@
 
 package com.iluwatar.featuretoggle.user;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
+import org.junit.jupiter.api.Test;
+
 /**
  * Test User Group specific feature
  */
 public class UserGroupTest {
 
   @Test
-  public void testAddUserToFreeGroup() throws Exception {
-    User user = new User("Free User");
+  public void testAddUserToFreeGroup() {
+    var user = new User("Free User");
     UserGroup.addUserToFreeGroup(user);
     assertFalse(UserGroup.isPaid(user));
   }
 
   @Test
-  public void testAddUserToPaidGroup() throws Exception {
-    User user = new User("Paid User");
+  public void testAddUserToPaidGroup() {
+    var user = new User("Paid User");
     UserGroup.addUserToPaidGroup(user);
     assertTrue(UserGroup.isPaid(user));
   }
 
   @Test
-  public void testAddUserToPaidWhenOnFree() throws Exception {
-    User user = new User("Paid User");
+  public void testAddUserToPaidWhenOnFree() {
+    var user = new User("Paid User");
     UserGroup.addUserToFreeGroup(user);
     assertThrows(IllegalArgumentException.class, () -> {
       UserGroup.addUserToPaidGroup(user);
@@ -58,8 +58,8 @@ public class UserGroupTest {
   }
 
   @Test
-  public void testAddUserToFreeWhenOnPaid() throws Exception {
-    User user = new User("Free User");
+  public void testAddUserToFreeWhenOnPaid() {
+    var user = new User("Free User");
     UserGroup.addUserToPaidGroup(user);
     assertThrows(IllegalArgumentException.class, () -> {
       UserGroup.addUserToFreeGroup(user);