Update our dependencies to their latest versions (where possibly)

Also adds Guava as a dependency as version upgrading our dependencies resulted in the loss of the included Guava libraries

src/test/java/com/gmail/nossr50/TestUtil.java

@@ -1,17 +0,0 @@
-package com.gmail.nossr50;
-
-import org.jetbrains.annotations.NotNull;
-
-import java.io.File;
-
-//TODO: Move generic test stuff here
-public class TestUtil {
-    public static void recursiveDelete(@NotNull File directoryToBeDeleted) {
-        if (directoryToBeDeleted.isDirectory()) {
-            for (File file : directoryToBeDeleted.listFiles()) {
-                recursiveDelete(file);
-            }
-        }
-        directoryToBeDeleted.delete();
-    }
-}

src/test/java/com/gmail/nossr50/database/FlatFileDatabaseManagerTest.java

@@ -1,6 +1,5 @@
 package com.gmail.nossr50.database;
 
-import com.gmail.nossr50.TestUtil;
 import com.gmail.nossr50.database.flatfile.LeaderboardStatus;
 import com.gmail.nossr50.datatypes.database.DatabaseType;
 import com.gmail.nossr50.datatypes.player.PlayerProfile;
@@ -86,7 +85,7 @@ public class FlatFileDatabaseManagerTest {
 
     @AfterEach
     public void tearDown() {
-        TestUtil.recursiveDelete(tempDir);
+        recursiveDelete(tempDir);
         db = null;
     }
 
@@ -844,4 +843,14 @@ public class FlatFileDatabaseManagerTest {
             return false;
         }
     }
+
+    public static void recursiveDelete(@NotNull File directoryToBeDeleted) {
+        if (directoryToBeDeleted.isDirectory()) {
+            for (File file : directoryToBeDeleted.listFiles()) {
+                recursiveDelete(file);
+            }
+        }
+        directoryToBeDeleted.delete();
+    }
+
 }

src/test/java/com/gmail/nossr50/util/blockmeta/ChunkStoreTest.java

@@ -1,6 +1,5 @@
 package com.gmail.nossr50.util.blockmeta;
 
-import com.gmail.nossr50.TestUtil;
 import com.gmail.nossr50.mcMMO;
 import com.gmail.nossr50.util.BlockUtils;
 import com.gmail.nossr50.util.compat.CompatibilityManager;
@@ -40,7 +39,7 @@ public class ChunkStoreTest {
 
     @AfterClass
     public static void tearDownClass() {
-        TestUtil.recursiveDelete(tempDir);
+        recursiveDelete(tempDir);
     }
 
     private World mockWorld;
@@ -440,4 +439,13 @@ public class ChunkStoreTest {
         Mockito.when(testBlock.getWorld()).thenReturn(mockWorld);
         return testBlock;
     }
+
+    public static void recursiveDelete(@NotNull File directoryToBeDeleted) {
+        if (directoryToBeDeleted.isDirectory()) {
+            for (File file : directoryToBeDeleted.listFiles()) {
+                recursiveDelete(file);
+            }
+        }
+        directoryToBeDeleted.delete();
+    }
 }