Task 'prepareReleaseUnitTestDependencies' not found in project ':app

Question

I'm struggling with an error when I try to run my app. The error that occurs is Task 'prepareReleaseUnitTestDependencies' not found in project ':app.

I have added the prepare release unit dependencies to the command line compiler under the settings but it hasn't made a difference?

Any advice?

The code below is from the app gradle.

apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.2"
    defaultConfig {
        applicationId "com.example.sjmplanningfinal"
        minSdkVersion 15
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner  "android.support.test.runner.AndroidJUnitRunner"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}


sourceSets {
    unitTest {
        java.srcDir file('src/test/java')
        resources.srcDir file('src/test/res')
     }
}

configurations {
    unitTestCompile.extendsFrom runtime
    unitTestRuntime.extendsFrom unitTestCompile

    dependencies {
        compile fileTree(dir: 'libs', include: ['*.jar'])
        androidTestCompile('com.android.support.test.espresso:espresso-    core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.3.1'
    compile 'com.android.support.constraint:constraint-layout:1.0.2'
    compile 'com.android.support:support-v4:25.3.1'
    testCompile 'junit:junit:4.12'
}