Error in using ArthurHub image crop library with kotlin

Question

I am using ArthurHub image crop library in my project. but this error occurs

Error:Execution failed for task ':app:transformDexArchiveWithExternalLibsDexMergerForDebug'.

java.lang.RuntimeException: java.lang.RuntimeException: com.android.builder.dexing.DexArchiveMergerException: Unable to merge dex

i have tried many solutions that were provided in other questions, but none of them works for me.

my build.gradle(module) file is here

apply plugin: 'com.android.application'
apply plugin: 'kotlin-android'

android {
compileSdkVersion 26
defaultConfig {
    applicationId "com.example.lenovo.chatapp"
    minSdkVersion 19
    targetSdkVersion 26
    versionCode 1
    versionName "1.0"
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
}

dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.android.support:design:26.1.0'
implementation 'com.android.support.constraint:constraint-layout:1.0.2'
implementation 'com.google.firebase:firebase-auth:12.0.0'
implementation 'com.android.support:support-v4:26.1.0'
implementation 'com.google.firebase:firebase-database:12.0.0'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.1'
androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.1'
compile "org.jetbrains.kotlin:kotlin-stdlib-jre7:$kotlin_version"
implementation 'de.hdodenhof:circleimageview:2.2.0'
implementation 'com.theartofdev.edmodo:android-image-cropper:2.6.+'
implementation 'com.google.firebase:firebase-core:12.0.0'
}
repositories {
mavenCentral()
}


apply plugin: 'kotlin-android-extensions'
apply plugin: 'com.google.gms.google-services'