fix gradle for kotlin version

Author: dawn-kgh

gradle/wrapper/gradle-wrapper.properties

@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.5-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-all.zip

kotlin/build.gradle

@@ -1,5 +1,5 @@
 buildscript {
-    ext.kotlin_version = '1.2.21'
+    ext.kotlin_version = '1.3.31'
 
     repositories {
         mavenCentral()
@@ -13,8 +13,9 @@ buildscript {
 apply plugin: 'kotlin'
 
 dependencies {
-    compile "org.jetbrains.kotlin:kotlin-stdlib-jre8:$kotlin_version"
-
+    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
+    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.0-M1'
+    
     testCompile "org.jetbrains.kotlin:kotlin-test"
     testCompile "org.jetbrains.kotlin:kotlin-test-junit"
 }