Add kotlin to project

app/build.gradle

@@ -1,4 +1,6 @@
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android-extensions'
+apply plugin: 'kotlin-android'
 
 android {
     compileSdkVersion 28
@@ -71,4 +73,8 @@ dependencies {
     implementation 'com.mikepenz:materialdrawer:6.1.2'
 
     implementation 'com.facebook.stetho:stetho:1.5.1'
+
+    implementation "androidx.core:core-ktx:1.1.0"
+    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.1.0"
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
 }

build.gradle

@@ -1,14 +1,16 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
-    
+    ext.kotlin_version = '1.3.50'
+
     repositories {
         google()
         jcenter()
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:3.5.0'
-        
+        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
@@ -19,6 +21,7 @@ allprojects {
     repositories {
         google()
         jcenter()
+        mavenCentral()
     }
     afterEvaluate {
         tasks.withType(JavaCompile.class) {

readropslibrary/build.gradle

@@ -1,4 +1,6 @@
 apply plugin: 'com.android.library'
+apply plugin: 'kotlin-android-extensions'
+apply plugin: 'kotlin-android'
 
 android {
     compileSdkVersion 28
@@ -45,4 +47,7 @@ dependencies {
     implementation 'io.reactivex.rxjava2:rxandroid:2.1.1'
     implementation 'org.jsoup:jsoup:1.11.3'
     implementation 'com.facebook.stetho:stetho-okhttp3:1.5.1'
+
+    implementation "androidx.core:core-ktx:1.1.0"
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
 }