The Firebase class is not being found for import

I've done the following process below:

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-v7:24.2.1'
    compile 'com.android.support:design:24.2.1'
    compile 'com.android.support:support-v4:24.2.1'
    compile 'com.android.support:cardview-v7:24.2.1'
    compile 'com.android.support:recyclerview-v7:24.2.1'

    compile "com.google.firebase:firebase-database:9.4.0"// banco
    compile 'com.google.firebase:firebase-auth:9.4.0' // autenticador 
    compile 'com.google.firebase:firebase-storage:9.4.0' //arquivos

    testCompile 'junit:junit:4.12'

}

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


buildscript {
    repositories {
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.2.2'
        classpath 'com.google.gms:google-services:3.0.0' // esse

    }
}

It looks like everything is correct, but I'm not able to declare a Firebase object.

Ex: Firebase novoObjeto;

The Firebase class is not being imported.

When I start typing Firebase , Firebaseapp ... and so on ... does not appear only Firebase so I can declare!