add kotlin classpath

build.gradle

@@ -1,6 +1,7 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
+    ext.kotlin_version = '1.3.30'
     repositories {
         google()
         jcenter()
@@ -9,6 +10,7 @@ buildscript {
         classpath 'com.android.tools.build:gradle:3.2.0'
         classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.4'
         classpath 'com.github.dcendents:android-maven-gradle-plugin:1.5'
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
@@ -21,6 +23,9 @@ allprojects {
         jcenter()
         flatDir { dirs 'libs' }
     }
+    tasks.withType(Javadoc).all {
+        enabled = false
+    }
 }
 
 task clean(type: Delete) {