Fix binding plugin and bump MockBukkit

build.gradle

@@ -117,7 +117,7 @@ dependencies {
 
     // Tests
     testImplementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.8.10'
-    testImplementation 'com.github.seeseemelk:MockBukkit-v1.19:2.141.0'
+    testImplementation 'com.github.seeseemelk:MockBukkit-v1.20:3.20.0'
     testImplementation('com.googlecode.json-simple:json-simple:1.1.1') {
         exclude group: 'junit', module: 'junit'
     }

src/main/java/com/onarandombox/MultiverseCore/MultiverseCore.java

@@ -151,6 +151,10 @@ public class MultiverseCore extends JavaPlugin implements MVCore {
      */
     @Override
     public void onDisable() {
+        if (serviceLocator == null) {
+            // TODO: This is a workaround while waiting for MockBukkit to fix their onDisable being called twice
+            return;
+        }
         this.saveAllConfigs();
         shutdownDependencyInjection();
         Logging.shutdown();

src/main/java/com/onarandombox/MultiverseCore/inject/binder/PluginBinder.java

@@ -30,6 +30,7 @@ public abstract class PluginBinder<T extends Plugin> extends AbstractBinder {
     protected final void configure() {
         var bindingBuilder = bindPlugin(getPlugin());
         bindingBuilder.to(Plugin.class);
+        bindPluginClass(bindingBuilder);
         bind(plugin.getLogger()).to(Logger.class);
     }