swapped to java 11

Server/build.gradle

@@ -11,7 +11,7 @@ compileJava {
 
 compileKotlin {
     kotlinOptions {
-        jvmTarget = JavaVersion.VERSION_1_8
+        jvmTarget = JavaVersion.VERSION_11
         freeCompilerArgs += '-XXLanguage:-NewInference'
     }
 }
@@ -47,4 +47,4 @@ jar {
         attributes 'Main-Class': 'rs09.Server'
     }
     from { configurations.compileClasspath.collect { it.isDirectory() ? it : zipTree(it) } }
-}
+}

build.gradle

@@ -12,8 +12,8 @@ allprojects {
     group = 'org.rs09'
     version = '1.0.0'
 
-    sourceCompatibility = 1.8
+    sourceCompatibility = 11
-    targetCompatibility = 1.8
+    targetCompatibility = 11
 
     repositories {
         mavenCentral()
@@ -27,7 +27,7 @@ allprojects {
 
     compileKotlin {
         kotlinOptions {
-            jvmTarget = "1.8"
+            jvmTarget = "11"
         }
     }
-}
+}