use SDK level 25 to build core

Author: codeanticode

core/build.xml

@@ -10,7 +10,7 @@
   <property name="core.jar.path" value="../android-core.zip" />
 
   <!-- Android platform to build the core library -->
-  <property name="android.platform" value="android-23" />
+  <property name="android.platform" value="android-25" />
 
   <!-- Wear version to build the core library -->
   <property name="wear.version" value="2.0.0" />	

gradle.properties

@@ -1,3 +1,3 @@
 // Set your Android SDK location and version here
 sdkdir=/Users/andres/code/android/sdk
-sdkver=23
+sdkver=25