title: Could not find com.google.firebase:firebase-core:9.0.0?
body: <p>In my app, I am trying to use gcm services, but I cannot even get gradle to compile. I keep getting the message that I am missing 'firebase core' though I have no idea how to install this.</p>
  
  <p>This is my top-level gradle file:</p>
  
  <pre><code>buildscript {
  repositories {
      jcenter()
  
  }
  dependencies {
      classpath 'com.android.tools.build:gradle:2.1.2'
      classpath "io.realm:realm-gradle-plugin:1.1.0"
      classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
      classpath 'com.google.gms:google-services:3.0.0'
    }
  }
  
  allprojects {
  repositories {
      jcenter()
      maven {
          url "https://jitpack.io"
      }
  
      maven {
          url "https://mint.splunk.com/gradle/"
      }
  }
  }
  </code></pre>
  
  <p>And here is my module-level gradle file:</p>
  
  <pre><code>apply plugin: 'com.android.application'
  apply plugin: 'realm-android'
  apply plugin: 'com.google.gms.google-services'
  
  
  android {
  
  compileSdkVersion 24
  buildToolsVersion "24.0.0"
  defaultConfig {
      applicationId "roof.android"
      minSdkVersion 17
      targetSdkVersion 23
      versionCode 11
      versionName "0.0.4"
  }
  buildTypes {
      release {
          minifyEnabled false
          proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
      }
  }
  packagingOptions {
      exclude 'META-INF/NOTIC E.txt'
      exclude 'META-INF/LICENSE.txt'
      exclude 'META-INF/maven/com.fasterxml.jackson.core/jackson-core/pom.properties'
      exclude 'META-INF/maven/com.fasterxml.jackson.core/jackson-core/pom.xml'
  }
  }
  
  dependencies {
  compile fileTree(include: ['*.jar'], dir: 'libs')
  
  // "The Android Support Library package contains several libraries that can be included in your application" -- https://developer.android.com/topic/libraries/support-library/features.html
  compile 'com.android.support:appcompat-v7:24.0.0'
  
  // "Native android recycler view library" -- https://developer.android.com/topic/libraries/support-library/features.html
  compile 'com.android.support:recyclerview-v7:24.0.0'
  
  // "A powerful image downloading and caching library for Android" -- http://square.github.io/picasso/
  compile 'com.squareup.picasso:picasso:2.5.2'
  
  // "Volley is an HTTP library that makes networking for Android apps easier and most importantly, faster" -- https://developer.android.com/training/volley/index.html
  compile 'com.android.volley:volley:1.0.0'
  
  // "JsonWebTokens in Auth0"  -- https://auth0.com/docs/jwt
  compile 'com.auth0:java-jwt:2.1.0'
  
  // "Joda-Time provides a quality replacement for the Java date and time classes" -- http://www.joda.org/joda-time/
  compile 'joda-time:joda-time:2.8.1'
  
  // "Android loading or progress dialog widget library, provide efficient way to implement iOS like loading dialog and progress wheel" -- https://github.com/Cloudist/ACProgressLite
  compile 'cc.cloudist.acplibrary:library:1.2.1'
  
  // "A RecyclerView that is powered by Realm and lots more" -- https://github.com/thorbenprimke/realm-recyclerview
  compile 'com.github.thorbenprimke:realm-recyclerview:0.9.22'
  
  // "A beautiful ripple animation for your app" -- https://github.com/skyfishjy/android-ripple-background
  compile 'com.skyfishjy.ripplebackground:library:1.0.1'
  
  // "A logger with a small, extensible API which provides utility on top of Android's normal Log class." -- http://jakewharton.github.io/timber/
  compile 'com.jakewharton.timber:timber:4.1.2'
  
  // "Field and method binding for Android views" -- http://jakewharton.github.io/butterknife/
  compile 'com.jakewharton:butterknife:8.1.0'
  apt 'com.jakewharton:butterknife-compiler:8.1.0'
  
  // "An HTTP+HTTP/2 client for Android and Java applications." -- http://square.github.io/okhttp/
  compile 'com.squareup.okhttp3:okhttp:3.3.1'
  
  // "Android client for Sentry"
  compile 'com.joshdholtz.sentry:sentry-android:1.4.1'
  
  compile 'com.google.android.gms:play-services-gcm:9.2.0'
  
  }
  </code></pre>