-Added dependencies for Google Auth

-Added Google sign in button--missing logic
-Updated gitignore to exclude config files for Google auth

Author: Nxt3

.gitignore

@@ -56,4 +56,5 @@ cd
 
 # Keystore files
 *.jks
-.signing/
+.signing/
+app/google-services.json

app/build.gradle

@@ -3,12 +3,12 @@ apply plugin: 'realm-android'
 apply plugin: 'me.tatarka.retrolambda'
 
 android {
-    compileSdkVersion 24
+    compileSdkVersion 25
     buildToolsVersion "25.0"
     defaultConfig {
         applicationId "io.havoc.todo"
         minSdkVersion 21
-        targetSdkVersion 24
+        targetSdkVersion 25
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
@@ -33,8 +33,9 @@ dependencies {
     })
 
     //Android Support Libraries
-    compile 'com.android.support:appcompat-v7:24.2.1'
-    compile 'com.android.support:design:24.2.1'
+    compile 'com.android.support:appcompat-v7:25.0.1'
+    compile 'com.android.support:design:25.0.1'
+    compile 'com.google.android.gms:play-services-auth:10.0.0'
 //    compile 'com.android.support.constraint:constraint-layout:1.0.0-alpha9'
 
     //Advanced RecyclerView
@@ -77,3 +78,6 @@ dependencies {
     //Testing
     testCompile 'junit:junit:4.12'
 }
+
+//Lord only knows why this has to be added at the bottom
+apply plugin: 'com.google.gms.google-services'

app/src/main/res/layout/activity_login.xml

@@ -10,4 +10,11 @@
     android:paddingTop="@dimen/activity_vertical_margin"
     tools:context="io.havoc.todo.view.activities.LoginActivity">
 
+    <com.google.android.gms.common.SignInButton
+        android:id="@+id/sign_in_button"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_centerHorizontal="true"
+        android:layout_centerVertical="true" />
+
 </RelativeLayout>

build.gradle

@@ -9,8 +9,7 @@ buildscript {
         classpath 'com.android.tools.build:gradle:2.2.2'
         classpath "io.realm:realm-gradle-plugin:2.0.2"
         classpath 'me.tatarka:gradle-retrolambda:3.3.0'
-        // NOTE: Do not place your application dependencies here; they belong
-        // in the individual module build.gradle files
+        classpath 'com.google.gms:google-services:3.0.0'
     }
 }