fix build for example project

Author: maxme

example/build.gradle

@@ -1,3 +1,12 @@
+buildscript {
+    repositories {
+        mavenCentral()
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:1.0.0'
+    }
+}
+
 apply plugin: 'com.android.application'
 
 android {