Update the android SDK version to 25

When using the current android studio with the current SDKs you have the problem that your app is on version 25 and you can not create a APK without adjusting the buildToolsVersion in the build.gradle

Author: markusguenther

android/build.gradle

@@ -11,8 +11,8 @@ buildscript {
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 23
-    buildToolsVersion "23.0.1"
+    compileSdkVersion 25
+    buildToolsVersion "25.0.0"
 
     defaultConfig {
         minSdkVersion 16