update 821 test

Author: fishercoder1534

src/test/java/com/fishercoder/firstthousand/_821Test.java

@@ -1,18 +1,18 @@
 package com.fishercoder.firstthousand;
 
 import com.fishercoder.solutions.firstthousand._821;
-import org.junit.BeforeClass;
-import org.junit.Test;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
 
 public class _821Test {
     private static _821.Solution1 solution1;
     private static _821.Solution2 solution2;
     private static int[] expected;
 
-    @BeforeClass
-    public static void setup() {
+    @BeforeEach
+    public void setup() {
         solution1 = new _821.Solution1();
         solution2 = new _821.Solution2();
     }