Update

commons/build.gradle

@@ -19,6 +19,7 @@ android {
 dependencies {
     compile fileTree(dir: 'libs', include: ['*.jar'])
     compile 'com.android.support:appcompat-v7:23.0.1'
+//    compile 'com.android.support:preference-v7:23.0.1'
     compile project(':core')
 }