Add SQLiteUpdateHook to proguard-rules (#206)

Without this, commit hooks don't always trigger.

Author: GrahamBorland

sqlite-android/proguard-rules.pro

@@ -11,5 +11,6 @@
 -keep public class io.requery.android.database.sqlite.SQLiteDatabase { *; }
 -keep public class io.requery.android.database.sqlite.SQLiteOpenHelper { *; }
 -keep public class io.requery.android.database.sqlite.SQLiteStatement { *; }
+-keep public class io.requery.android.database.sqlite.SQLiteUpdateHook { *; }
 -keep public class io.requery.android.database.CursorWindow { *; }
 -keepattributes Exceptions,InnerClasses