Remove fabric and firebase from android studio project completely

I am getting struggled with errors and warnings whenever I try to remove fabric and firebase from my android studio project. I almost deleted every implementation of those from project but I still see some crashlytics in my gradle. How can I clean up these fully. I don't want any firebase/fabric in my project.

My app level Gradle:

buildscript {
repositories {
    maven { url 'https://maven.fabric.io/public' }
}

dependencies {
    classpath 'io.fabric.tools:gradle:1.+'
}
}
apply plugin: 'com.android.application'
apply plugin: 'io.fabric'

repositories {
maven { url 'https://maven.fabric.io/public' }
}


android {
compileSdkVersion 26
defaultConfig {
    applicationId 'drpg.ddkeys'
    minSdkVersion 19
    targetSdkVersion 26
    versionCode 4
    versionName '4.4.42'
    testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    lintOptions {
        checkReleaseBuilds false
        abortOnError false
    }
    versionNameSuffix 'blaze'
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
productFlavors {
}
buildToolsVersion '27.0.3'
}

dependencies {
implementation fileTree(include: ['*.jar'], dir: 'libs')
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.android.support:design:26.1.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
implementation 'com.android.support:support-v4:26.1.0'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso- 
core:3.0.2'

}

apply plugin: 'com.google.gms.google-services'

My Project level gradle:

buildscript {
repositories {
    maven { url 'https://maven.fabric.io/public' }
}

dependencies {
    classpath 'io.fabric.tools:gradle:1.+'
}
}
apply plugin: 'com.android.application'
apply plugin: 'io.fabric'

repositories {
maven { url 'https://maven.fabric.io/public' }
}


android {
compileSdkVersion 26
defaultConfig {
    applicationId 'drpg.ddkeys'
    minSdkVersion 19
    targetSdkVersion 26
    versionCode 4
    versionName '4.4.42'
    testInstrumentationRunner 
    "android.support.test.runner.AndroidJUnitRunner"
    lintOptions {
        checkReleaseBuilds false
        abortOnError false
    }
    versionNameSuffix 'blaze'
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 
'proguard-rules.pro'
    }
}
productFlavors {
}
buildToolsVersion '27.0.3'
}

dependencies {
implementation fileTree(include: ['*.jar'], dir: 'libs')
implementation 'com.android.support:appcompat-v7:26.1.0'
implementation 'com.android.support:design:26.1.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
implementation 'com.android.support:support-v4:26.1.0'
testImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test.espresso:espresso- 
core:3.0.2'
}

apply plugin: 'com.google.gms.google-services'