Testfairy sdk not working in Pre Kitkat version in Android
<p>I am new to android developer. I integrate testfairy sdk in my own app. An app is working on kitkat, Lollipop,Marshmallow  and Nougat. I got the issues when run an app in JellyBean Mobile. Other library cause error.</p>

<blockquote>
  <p>Could not find class 'com.testfairy.m', referenced from method com.testfairy.TestFairy.b
   java.lang.NoClassDefFoundError: com.wdullaer.materialdatetimepicker.R$string</p>
</blockquote>

<pre><code>apply plugin: 'com.android.application'

android {
    packagingOptions {
        pickFirst 'META-INF/LICENSE.txt'
        exclude 'META-INF/DEPENDENCIES'
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/NOTICE.txt'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/LICENSE.txt'
    }
    compileSdkVersion 23
    buildToolsVersion "24.0.1"


    dexOptions {
        javaMaxHeapSize "4g"
    }

    defaultConfig {
        applicationId "com.ephron.coolspa"
        minSdkVersion 14
        targetSdkVersion 18
        versionCode 1
        versionName "1.0"
        multiDexEnabled true
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
    sourceSets {
        main {
            res.srcDirs = ['src/main/res', 'src/main/res/anim']
            assets.srcDirs = ['src/main/assets', 'src/main/assets/']
        }
    }
}

dependencies {
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:design:22.2.1'
    compile files('libs/httpclient-4.5.2.jar')
    compile files('libs/httpcore-4.4.4.jar')
    compile 'com.squareup.picasso:picasso:2.5.2'
    compile 'com.google.android.gms:play-services:8.4.0'
    compile files('libs/gcm.jar')
    compile 'com.google.android.gms:play-services-maps:8.4.0'
    compile 'com.github.rahatarmanahmed:circularprogressview:2.5.0'
    compile 'com.sun.mail:android-mail:1.5.6'
    compile 'com.sun.mail:android-activation:1.5.5'
    compile project(':library')
    compile 'com.wdullaer:materialdatetimepicker:2.5.0'
    compile 'me.biubiubiu.justifytext:library:1.1'
    compile 'testfairy:testfairy-android-sdk:1.+@aar'

}

//TestFairy start - autogenerated by TestFairy intellij plugin
//manual changes might get overwritten
buildscript {
    repositories {
        mavenCentral()
        maven { url 'https://www.testfairy.com/maven' }
    }
    dependencies {
        classpath 'com.testfairy.plugins.gradle:testfairy:1.+'
    }
}
apply plugin: 'testfairy'
android {
    testfairyConfig {
        apiKey 'da1938b1a6b158583a45a9d1fee3e09ad1add4a7'
    }
}
//TestFairy end
</code></pre>